The war in Donbas, also called the Donbas war, was a phase of the Russo-Ukrainian war in the eastern Donbas region of Ukraine. The war began in April 2014, when Russian-backed paramilitaries began an uprising against the Ukrainian government, seized territory and declared independent states. Ukraine's military launched an operation against them, but failed to fully retake the territory. Covertly, Russia's military were directly involved, and the separatists were largely under Russian control. This phase ended when the war was subsumed by the full-scale Russian invasion of Ukraine in 2022. In March 2014, following Ukraine's Revolution of Dignity, Russia occupied Crimea. Anti-revolution and pro-Russian protests began in Ukraine's Donetsk and Luhansk provinces, collectively 'the Donbas'. On 12 April, a commando unit led by Russian citizen Igor 'Strelkov' Girkin crossed the border from Russia and seized Sloviansk and other settlements in the Donbas. Separatists declared the Donetsk and Luhansk republics (DPR and LPR) as independent states. Russia covertly supported them with soldiers and weaponry. It only admitted sending "military specialists", but later acknowledged the separatists as Russian combat veterans. On 15 April, Ukraine began an "Anti-Terrorist Operation" (ATO). By August 2014, Ukraine had re-taken most of its territory. Russia reacted by covertly sending troops, tanks and artillery into the Donbas, helping pro-Russian forces regain much of what they had lost. DPR leader Alexander Borodai said 50,000 Russian citizens had fought for the separatists by mid-2015, excluding the regular Russian troops that invaded. The Minsk agreement was signed in September 2014. There was to be a ceasefire monitored by the OSCE; release of prisoners; withdrawal of illegal armed groups and foreign soldiers from Ukraine; withdrawal of heavy weaponry; elections in the Donbas under Ukrainian law; and granting self-governance ("special status") to rebel-held territories. On 16 September, Ukraine passed a law to grant this self-governance and schedule elections there for December. However, the separatists held their own elections in November, which violated the Minsk agreement. The ceasefire was also broken, and Russian-backed forces began an assault on Donetsk Airport, eventually capturing it in January 2015. A new ceasefire, Minsk II, was agreed on 12 February 2015. Immediately after, Russian forces renewed their offensive on Debaltseve and forced Ukraine's military to withdraw. Both sides fortified their position by building networks of trenches, bunkers and tunnels, resulting in static trench warfare. Donbas remained a war zone, with dozens killed monthly. OSCE observers documented military convoys crossing from Russia covertly, and by the end of 2017 had counted around 30,000 people in military gear crossing from Russia at the two border checkpoints it was allowed to monitor. All sides agreed to the "Steinmeier formula" for ending the war in October 2019. Following a ceasefire and withdrawal of foreign soldiers, elections would be held under Ukrainian law and, if the OSCE deemed these free and fair, then the Donbas territories would be given "special status" and re-integrated into Ukraine. The Ukrainian side demanded control of its border and the right of internally displaced Ukrainians to return to the Donbas to vote. The Donbas separatists said they would not withdraw or disarm, refused to give up control of the border, and said they would seek integration with Russia. The Russian state continued to deny that its military was in the Donbas, insisting that elections be held while Russian and Russian-backed forces still controlled the territory and the border. During 2021, Russia's proxies stepped up their attacks as Russian forces massed near Ukraine's borders. Russia recognised the DPR and LPR as independent states on 21 February 2022 and deployed "peacekeeping" troops there. On 24 February, Russia began a full-scale invasion of Ukraine, subsuming the Donbas war into it. About 14,000 people were killed in the war: 6,500 Russian and Russian proxy forces, 4,400 Ukrainian forces, and 3,400 civilians on both sides. Most civilian casualties were in the first year. In 2011, Luhansk and Donetsk oblasts had a combined population of 6.1 million. As a result of the Donbas war, 2 million fled the region.
Background
Despite being recognised as an independent country since 1991, as a former USSR constituent republic, Ukraine was perceived by the leadership of Russia as part of its sphere of influence. In a 2002 paper Taras Kuzio stated "While accepting Ukrainian independence, Putin has sought to draw Ukraine into a closer relationship. This approach has been acceptable to eastern Ukrainian oligarchs, who do not harbour anti-Russian feelings". In 2011, Kuzio stated:
The traditional Soviet policy of dividing eastern against western Ukrainians, then "bourgeois nationalists" and now "crazy Galicians", remains in place. This tactic was deliberately employed by the Yanukovych administration is promoting a strategy of regional divide-and-rule through polarisation, using 9 May–style provocations, to maintain its eastern Ukrainian electorate permanently mobilised. Analysts have stated that as of February 2014, Russia was able to:
Control and manipulate the price of gas shipments to Ukraine's disadvantage (in the past few years, it had twice turned off the flow of gas to the country to force the hands of Ukrainian leaders); Arbitrarily impose trade restrictions on Ukrainian exports; Flood Ukraine with television propaganda highlighting alleged Western interference in Ukraine's internal affairs; Stir up secessionist sentiment in Russian-speaking areas such as Crimea and Donetsk. The Ukrainian state has also alleged infiltration of its security services by Russian state operatives in the lead-up to the events of 2014. According to the Institute of Modern Russia, the Kremlin also maintained a tight hold on Ukraine's president, Viktor Yanukovych.
Ukrainian revolution
In November 2013, the 'Euromaidan' protests began in response to Yanukovych's sudden decision to abandon a political association and free trade agreement with the European Union (EU), instead choosing closer ties to Russia. Earlier that year, Ukraine's parliament had overwhelmingly approved finalising the agreement with the EU. Russia had put pressure on Ukraine to reject it. The scope of the protests widened, with calls for Yanukovych's resignation. Protesters opposed what they saw as government corruption and abuse of power, oligarchic sway, police brutality and human rights violations. On 28 January 2014, Ukraine's government resigned. The protests climaxed on 18–20 February 2014 with clashes in Kyiv between protesters and Berkut special riot police, in which 108 protesters were killed; most of them were shot by snipers. On 21 February, President Yanukovych and the opposition signed an agreement to bring about an interim unity government, early elections, and urgent constitutional changes (which needed to be signed by the president). However, Yanukovych secretly fled the city that evening. The next day, parliament voted to remove him from office. About 73% of the parliament and members of all parties voted to remove him, including members of his own party. On 27 February, an interim government was established and early presidential elections were scheduled. This series of events became known as the Revolution of Dignity. Immediately following the revolution, unmarked Russian troops occupied the Ukrainian territory of Crimea. After an illegal referendum, Crimea was annexed by Russia.
Protests in the Donbas
Following the revolution, counter-revolutionary and pro-Russian protests began in parts of the Donbas. In the last census, the population of the Donbas was about 58% ethnic Ukrainian and 38% ethnic Russian overall: Donetsk Oblast was 57% Ukrainian and 38% Russian, while Luhansk Oblast was 58% Ukrainian and 39% Russian. A national survey held in March–April 2014 found that 58% of respondents in the Donbas wanted autonomy within Ukraine and 31% wanted secession. The Donbas was the region most strongly supportive of Yanukovych and his Party of Regions. People in the Donbas mostly consumed Russian-based media, which portrayed Ukraine's new interim government as an illegitimate "fascist junta" and that ethnic Russians were in imminent danger. Leaked e-mails and telephone calls later revealed that the Russian state had funded and organized separatists, mainly through Kremlin advisers Vladislav Surkov and Sergey Glazyev. Pro-Russian protesters occupied the Donetsk Regional State Administration Building from 1 to 6 March 2014, until the SBU removed them. Pavel Gubarev was proclaimed "people's governor" of Donetsk Oblast and Aleksandr Kharitonov "people's governor" of Luhansk Oblast. Ukrainian authorities arrested local separatist leaders in early March. They were replaced by figures linked to the Russian security services. Political scientist Taras Kuzio wrote that Russia transformed the protesters "into armed insurgents; this was never an organic process". On 6 April, 1,000–2,000 demonstrators in Donetsk demanded a referendum on autonomy or accession to Russia, similar to the one held in Crimea in March. Hundreds of masked men seized weapons from the SBU building in the city, and a large crowd stormed and occupied the Donetsk RSA building, raising the Russian flag. They demanded the regional council vote for a referendum on joining Russia the next day, vowing to otherwise take control of the regional government with a "people's mandate", dismissing all elected regional councillors and members of parliament. As these demands were not met, the following day the activists proclaimed the Donetsk People's Republic (DPR) as an independent state. Unrest also began in Luhansk on 6 April, when hundreds of protesters besieged the SBU headquarters for six hours, demanding the release of anti-government militants held there. They eventually stormed and occupied the building, releasing prisoners and seizing weapons. The Minister of Internal Affairs, Arsen Avakov, said on 9 April 2014 the separatist occupation of Ukrainian government buildings in the Donbas would be ended within 48 hours, by negotiation or force, declaring, "we are ready for both". Acting President Oleksandr Turchynov had already ordered the seized Donetsk regional administration building placed "under state protection", and offered amnesty to separatists who disarmed and surrendered. On 11 April, Prime Minister Arseniy Yatsenyuk was reported as saying, while he was opposed to the use of force, there are limits to everything.
First phase of the war (2014)
While the initial protests were largely native expressions of discontent with the new Ukrainian government, Russia took advantage of them to launch a coordinated political and military campaign against Ukraine. Russian citizens led the separatist movement in Donetsk from April 2014, and were supported by volunteers and materiel from Russia. As the conflict escalated in May 2014, Russia employed a "hybrid approach", deploying a combination of disinformation, irregular fighters, regular Russian troops, and conventional military support to destabilise the Donbas.
Militants seize towns
Between 12 and 14 April 2014, Russian militants took control of government buildings in several towns and cities in Donetsk oblast, including Sloviansk, Kramatorsk, Druzhkivka, Horlivka, Mariupol, Yenakiieve, Makiivka and Zhdanivka.
Sloviansk
On 12 April 2014, a heavily-armed Russian paramilitary unit crossed the border from Russia into Ukraine and seized the strategic town of Sloviansk. They attacked and occupied the town's administration building, police station, and SBU building, seized weapons, and set up roadblocks with the help of local armed activists. The militants wore no insignia and had been sent from occupied Crimea via Russia. The unit was made up of fifty Russian Armed Forces volunteers, commanded by former GRU colonel Igor 'Strelkov' Girkin, a right-wing Russian nationalist associated with the neo-imperialist movement. In an interview for Russian ultranationalist newspaper Zavtra, he said that this action sparked the war in eastern Ukraine:"I'm the one who pulled the trigger of this war. If our unit hadn't crossed the border, everything would have fizzled out, like in Kharkiv or Odesa".
Girkin explained that "nobody there wanted to fight" until his unit seized Sloviansk. Pro-Russian militants unlawfully detained journalists (including American Simon Ostrovsky), local civilians, and the elected mayor, Nelya Shtepa. On 25 April, they kidnapped eight OSCE observers and held them captive, claiming they were "NATO spies". The militants also carried out several summary executions. Girkin later took responsibility for these. According to Serhiy Kudelia in Seize the City, Undo the State: The Inception of Russia's War on Ukraine, "None of the local activists who organized the first anti-Kyiv protests in Sloviansk played any prominent role once Girkin seized the town". Although some joined the paramilitaries, they were commanded by outsiders; "separatist resistance in Sloviansk was thus fully subordinated to the interests of a small group of Russian citizens acting in coordination with their Moscow chiefs".
Kramatorsk
The same day as the capture of Sloviansk, Girkin's men attacked the police station in nearby Kramatorsk, resulting in a shootout. The fighters, claiming to be members of the Donbas People's Militia, later captured the police station. They removed the police station's sign and raised the flag of the Donetsk People's Republic over the building. They then issued an ultimatum that stated that if the city's mayor and administration did not swear allegiance to the Republic by the following Monday, they would remove them from office.
Horlivka
Pro-Russian militants attempted to seize the police headquarters in Horlivka on 12 April, but were halted. Ukrainska Pravda reported that police said that the purpose of the attempted seizure was to gain access to a weapons cache. They said that they would use force if needed to defend the building from "criminals and terrorists". By 14 April militants had captured the building after a tense standoff with the police. Some members of the local police unit had defected to the Donetsk People's Republic earlier in the day, whilst the remaining officers were forced to retreat, allowing the insurgents to take control of the building. The local chief of police was captured and badly beaten by the insurgents. A Horlivka city council deputy, Volodymyr Rybak, was kidnapped by masked men believed to be pro-Russian militants on 17 April. His body was later found in a river in occupied Sloviansk on 22 April. The city administration building was seized on 30 April, solidifying separatist control over Horlivka.
==== Other settlements ==== Other smaller towns, as well as government buildings, were seized by Russian-backed militants in the Donbas. In Artemivsk (Bakhmut) on 12 April, separatists failed to capture the local Ministry of Internal Affairs office, but instead captured the city administration building and raised the DPR flag over it. The city administration buildings in Yenakiieve and Druzhkivka were also captured. Police repelled an attack by pro-Russian militants upon an office of the Ministry of Internal Affairs in Krasnyi Lyman on 12 April, but the building was later captured by the separatists after a skirmish. Insurgents affiliated with the Donbas People's Militia occupied a regional administration building in Khartsyzk on 13 April, followed by a local administration building in Zhdanivka on 14 April. On 12 April, unmarked pro-Russian militants seized the Donetsk headquarters of the Interior Ministry and two police stations without resistance, while an assault on the general prosecutor's office was repelled. Following negotiations between the militants and those in the building, the chief of the office resigned from his post. According to anonymous witnesses, some militants wore uniforms of the Berkut special police force, which had been dissolved by the new government following the February revolution. The militants also took over the municipal administration building unopposed on 16 April. Demonstrators hoisted the DPR flag over the city administration buildings in Krasnoarmiisk and Novoazovsk on 16 April. The local administration building in Siversk was similarly captured on 18 April. Following the takeover, local police announced that they would co-operate with the activists.
Beginning of government "Anti-Terrorist Operation"
The first conflict deaths in the Donbas occurred on 13 April, when the Russian paramilitaries who occupied Sloviansk fired on Ukrainian SBU officers on the city outskirts. Ukrainian Alpha Group captain Gennady Bilichenko was killed and several wounded, while at least one Russian militant was killed by return fire. In response to the separatist takeover of Sloviansk and Kramatorsk, attacks on government forces and police stations in the Donbas, and their refusal to surrender, Turchynov announced that Ukrainian forces would launch an "Anti-Terrorist Operation" on 15 April. However, Ukrainian forces were poorly prepared, and the operation soon stalled. Russian paramilitary commander Igor Strelkov said that Ukrainian forces were "extremely cautious" at first, as Russian troops were massed on Ukraine's border and the Ukrainians were unsure how Russia would respond.
As part of this counter-offensive, in the Battle of Kramatorsk, Ukrainian special forces re-took Kramatorsk Airfield on 15 April, after a skirmish with the Donbas People's Militia. Ukrainian officials and Russian media said at least four rebels were killed and several captured. Outside the airfield, angry protesters surrounded Ukrainian unit commander Lt. Gen. Vasyl Krutov and demanded to know why troops had "fired on locals". Krutov said the unrest was being led by Russian forces and "We need to destroy this foreign invader". On 16 April, Ukraine's 25th Airborne Brigade entered Kramatorsk in columns of BMD-2 infantry fighting vehicles. They were blocked by crowds of civilians "with members of a Russian diversionary-terrorist group among them", according to Ukraine's defense ministry. One of the columns was surrounded and disarmed, and their six armored vehicles were captured by Russian paramilitaries, who drove them to Sloviansk. The same day, a large crowd backed by Russian paramilitaries halted another Ukrainian armored column in Pchyolkino, letting them go only after soldiers surrendered their rifle magazines. Because of this, Turchynov announced he would disband the brigade, although this was later cancelled.
In Mariupol on 17 April, three members of the Donbas People's Militia were killed, 11 wounded and 63 arrested after a failed assault on a Ukrainian National Guard base. On 17 April 2014, an agreement was signed in Geneva by representatives of Russia, Ukraine, the EU and the US. It called for a ceasefire in the Donbas, for all illegal armed groups to disarm, and for all illegally occupied buildings and public places to be vacated. The pro-Russian paramilitaries refused to leave occupied buildings and refused to disarm until the Ukrainian nationalist group Right Sector disarmed. The Ukrainian government announced on 19 April 2014 that it had paused its counter-offensive in the Donbas.
Re-launch of Ukrainian operation
Ukraine re-launched the stalled operation against pro-Russian paramilitaries on 22 April, after the body of local councillor Volodymyr Rybak was found dumped in a river near Sloviansk. He had been kidnapped on 17 April by pro-Russian militants after he tried to re-raise the Ukrainian flag over Horlivka city council building. The bodies of Maidan activists Yuri Popravko and Yuri Diakovskyi were also found in the river. All three had been kidnapped, tortured, mutilated and killed by pro-Russian militants. They were the first civilians killed by pro-Russian forces in the Donbas war. Turchynov said that "the terrorists who effectively took the whole Donetsk Oblast hostage have now gone too far". Pro-Russian militants kidnapped more than two dozen people, including journalists such as Simon Ostrovsky. On 22 April, the offices of a newspaper in Kostiantynivka were burnt down, after receiving threats for criticizing the militants. On 21 April, demonstrators gathered for a "people's assembly" outside the SBU building in Luhansk and called for a "people's government", demanding either federalisation or joining Russia. At this assembly, they elected Valery Bolotov as "People's Governor". Two referendums were announced, one to be held on 11 May to determine whether Luhansk region should seek greater autonomy, and another scheduled for 18 May to determine whether the region should join Russia, or declare independence. The Internal Affairs Ministry reported that the city of Sviatohirsk, near Sloviansk, was retaken by Ukrainian troops on 23 April. In addition, the Defence Ministry said it had taken control over all points of strategic importance in the area around Kramatorsk. On 24 April 70 to 100 insurgents armed with assault rifles and rocket launchers attacked an armoury in Artemivsk. The depot housed around 30 tanks. Ukrainian troops attempted to fight off the insurgents, but were forced to retreat after many men were wounded by insurgent fire. Some 30 militants seized the police headquarters in Konstantinovka on 28 April.
On 24 April, Avakov said that Ukrainian troops had captured the city administration in Mariupol, after a clash with pro-Russian demonstrators there. Despite this, a report by the BBC said that whilst it appeared that Ukrainian troops and the mayor of Mariupol did enter the building in the early morning, Ukrainian troops had abandoned it by the afternoon. Local pro-Russian activists blamed Ukrainian nationalists for the attack upon the building but said that the DPR had regained control. A representative of the Republic, Irina Voropoyeva, said, "We, the Donetsk People's Republic, still control the building. There was an attempted provocation but now it's over." The same day, Ukrainian government officials said that the Armed Forces had intended to retake the city of Sloviansk, but that an increased threat of "Russian invasion" halted these operations. Russian forces had mobilised within 10 kilometres (6+1⁄4 mi) of the Ukrainian border. By 6 May 14 Ukrainian troops had died and 66 had been injured in the fighting. Insurgents took over the offices of the regional state television network on 27 April. After capturing the broadcasting centre, the militants began to broadcast Russian television channels. The Luhansk People's Republic (LPR) was declared on 27 April. Representatives of the Republic demanded that the Ukrainian government provide amnesty for all protesters, enshrine Russian as an official language, and hold a referendum on the status of the region. They issued an ultimatum that stated that if Kyiv did not meet their demands by 14:00 on 29 April, they would launch an insurgency in tandem with that of the Donetsk People's Republic. On 29 April, a city administration building in Pervomaisk was overrun by Luhansk People's Republic insurgents, who then raised their flag over it. In Krasnyi Luch, the city administration conceded to demands by separatist activists that it support the referendums on the status of Donetsk and Luhansk of 11 May, and followed by raising the Russian flag over the city administration building. Insurgents occupied the city administration building in Kadiivka on 1 May. Later in the week, they captured the local police station, business centre, and SBU building. The same day, the police headquarters in Slovianoserbsk was seized by members of the Army of the South-East, affiliated with the Luhansk People's Republic. The town of Antratsyt was occupied by a number of renegade Don Cossacks. Insurgents went on to seize the prosecutor's office in Sievierodonetsk on 7 May. The next day, supporters of the Luhansk People's Republic captured government buildings in Starobilsk. After a government counter-offensive as part of the "Anti-Terrorist Operation" in Donetsk Oblast on 2–3 May, the insurgents were routed from Kramatorsk's occupied SBU building. Despite this, Ukrainian troops quickly withdrew from the city for unknown reasons, and the separatists quickly regained control. Sporadic fighting continued until 5 July, when the insurgents withdrew from Kramatorsk.
In Mariupol, the city administration building was briefly retaken by the Ukrainian National Guard on 7 May. The pro-Russian forces quickly took the building back. Ukrainian troops launched another attack on insurgents in Mariupol on 9 May. A police building occupied by insurgents was set alight by government forces, causing the insurgents to flee. Internal Affairs minister Avakov said that 60 insurgents attacked the police building, not Ukrainian troops and that the police and other government forces repelled the insurgents. Between six and twenty militants were killed, along with one police officer. Four militants were captured, and five policemen were wounded. During the fighting, pro-Russian protesters seized one armoured personnel carrier, and afterwards barricaded the city centre with tyres. The same day, separatists attempting to disarm Ukrainian troops near Donetsk were met with warning shots, and 100 were detained. A priest from the Ukrainian Orthodox Church (Moscow Patriarchate) attempted to negotiate with separatists near Druzhkivka, but was later killed on 9 May, being shot eight times.
May 2014: post-referendum fighting
It was reported on 12 May that, following the local autonomy referendum, the Donbas People's Militia leader Igor Girkin declared himself "Supreme Commander" of the Donetsk People's Republic. In his decree, he demanded that all military stationed in the region swear an oath of allegiance to him within 48 hours, and said that all remaining Ukrainian military in the region would be "destroyed on the spot". He then petitioned the Russian Federation for military support to protect against "the threat of intervention by NATO" and "genocide". Pavel Gubarev, president of Donetsk People's Republic, instituted martial law on 15 May, and vowed for "total annihilation" of Ukrainian forces if they did not pull out of the Donbas by 21:00. Similarly, the president of the Luhansk People's Republic, Valery Bolotov, declared martial law on 22 May. The Donetsk-based steel magnate Rinat Akhmetov called on his 300,000 employees within the Donetsk region to "rally against separatists" on 20 May. Sirens sounded at noon at his factories to signal the beginning of the rally. A so-called "Peace March" was held in the Donbas Arena in Donetsk city, accompanied by cars sounding their horns at noon. BBC News and Ukrainska Pravda reported that some vehicles were attacked by separatists, and that gunmen had warned the offices of several city taxi services not to take part. On 16 May, Metinvest steelworkers, along with local police and security forces, routed the insurgents from the city administration and other occupied government buildings in the city. Most insurgents left the city, but some could still be seen outside the burnt city administration building.
On 22 May 18 Ukrainian soldiers were killed during an insurgent attack upon an army checkpoint near the city of Volnovakha. Three armoured personnel carriers and several lorries were destroyed in the attack, whilst one insurgent was killed. The same day, a convoy consisting of 100 soldiers attempted to cross a bridge at Rubizhne, Luhansk Oblast, and advance into insurgent-held territory. They were ambushed by a group of between 300 and 500 insurgents. After fighting that lasted throughout the day, the soldiers were forced to retreat. Between two and fourteen soldiers and between seven and twenty insurgents were killed during the fighting. Three army infantry combat vehicles and one lorry were destroyed, and another three armoured vehicles were captured by the insurgents. The Internal Affairs Ministry stated that some insurgents had attempted to enter Luhansk Oblast from Russia, but had been repelled by border guards. Following a declaration by Pavel Gubarev establishing the "New Russia Party" on 22 May, representatives of the Donetsk and Luhansk republics signed an agreement creating the confederative state of New Russia. Separatists planned to incorporate most of Ukraine's southern and eastern regions into the new confederation, including the key cities of Kharkiv, Kherson, Dnipropetrovsk, Mykolaiv, Zaporizhzhia and Odesa. The declaration signed established the position of Russian Orthodoxy as the state religion and an intention to nationalise key industries.
A unit of the pro-government Donbas Battalion volunteer paramilitary attempted to advance on a separatist checkpoint near the village of Karlivka, northwest of Donetsk city, on 23 May. They were ambushed by a group of between 150 and 200 separatists, supported by one of the captured armoured personnel carriers. The pro-government paramilitary was surrounded by the separatists, and outnumbered six to one until fighters affiliated with the nationalist Right Sector broke through the separatist lines to allow some members of the group to escape. Five members of the Donbas Battalion were killed, along with four separatists. Twenty members of the pro-government paramilitaries were wounded, and at least four were captured. The involvement of Right Sector was disputed by the leadership of the Donbas Battalion. Pro-Russian leader Igor Bezler said that he executed all of the captured paramilitaries. Another separatist leader confirmed four of their fighters were killed, and also said that ten pro-government paramilitaries and two civilians died. During the same day, two pro-Russian separatists were killed during an assault by the pro-government "Ukraine Battalion" paramilitary on an occupied local government building in Torez.
Escalation in May and June 2014
First Battle of Donetsk Airport
On the morning of 26 May 200 pro-Russian insurgents, including members of the Vostok Battalion, captured the main terminal of the Donetsk International Airport, erected roadblocks around it, and demanded that government forces withdraw. The Ukrainian National Guard issued an ultimatum to the separatists, asking them to surrender. This was rejected. Government forces then launched an assault on separatist positions at the airport with paratroopers and airstrikes. Attack helicopters were used by government forces. They targeted a separatist-operated anti-aircraft gun. An estimated 40 insurgents died in the fighting, with some civilians caught in the crossfire. Between 15 and 35 insurgents were killed in a single friendly-fire incident, when two lorries carrying wounded fighters away from the airport were ambushed by insurgents mistaking them for Ukrainian forces. During the fighting at the airport, Druzhba Arena in Donetsk city was ransacked by pro-Russian insurgents, who looted the building and destroyed surveillance equipment, and set it ablaze. Concurrently, Donetsk police said the insurgents had killed two policemen in the nearby town of Horlivka. The Moscow Times reported that the two men had been executed for "breaking their oath to the Donetsk People's Republic". Mykhailo Koval, the Minister of Defence, said on 30 May that Ukrainian government forces had "completely cleared" the insurgents from the southern and western parts of Donetsk Oblast and the northern part of Luhansk Oblast. Meanwhile, an internal coup replaced the leadership of the Donetsk People's Republic, and some bodies of Russian fighters killed in the airport battle were repatriated to Russia.
Luhansk border post siege
Two separatists were killed in a skirmish with Ukrainian border guards on 31 May. Two days later, five separatists were killed when 500 separatists attacked a border post in Luhansk Oblast. Eleven border guards and eight separatists were wounded during the fighting, which also killed one civilian.
2 June Luhansk airstrike
On 2 June, eight people were killed and more than 20 wounded by a series of explosions hitting the occupied RSA building in Luhansk city. Separatists blamed the incident on a government airstrike, while Ukrainian officials denied this, and claimed that the explosions were caused by a stray surface-to-air missile fired by insurgents. The Organisation for Security and Co-operation in Europe (OSCE) published a report the next day, stating that based on "limited observation", they believed that the explosion was caused by an airstrike, supporting separatist claims. A CNN investigation found clear evidence that the attack came from the air and the pattern of the craters suggested use of standard equipment on the Su-25, a ground-attack fighter, and the Su-27 – both combat aircraft operated by Ukraine. Although the Russian Federation also uses Sukhoi Su-27, it was not mentioned in the CNN news article as even a possibility. Radio Liberty also concluded that "Despite Denials, All Evidence For Deadly Explosion Points To Kyiv". CNN said that it was the first time that civilians had been killed in an attack by the Ukrainian air force during the 2014 pro-Russian unrest in the Donbas. The next day, Luhansk People's Republic declared a three-day mourning in the city.
