Local separatists, some directed and financed by the Russian security services,[15] took advantage of the situation and occupied government buildings in Donetsk, Luhansk, and Kharkiv oblasts in early March 2014.

[17] In the second phase from April 2014, armed Russian-backed groups seized government buildings across Donetsk and Luhansk oblasts, together known as the Donbas, and launched a separatist insurgency in the region.

[20] After the 2004 Orange Revolution, Russia launched a decade-long effort to restore its political influence in Ukraine by playing on existing domestic fault lines and undermining the central government.

Russia actively supported the separatism in Ukraine, including using its high-level actors, such as Kremlin advisers Vladislav Surkov and Sergey Glazyev, who organized some of the pro-russian protests.

[58] In interviews with OSCE monitors, bystanders described how a group of around thirty pro-Maidan protesters "were forced to seek shelter in a police bus that became surrounded by anti-Maidan attackers".

[94][95] A report by the OSCE said that "police forces" failed "to take adequate measure to protect the pro-Maidan assembly", and "could be observed treating the anti-Maidan protesters in a favourable manner".

[107] The political leader of the state was the self-declared People's Governor Pavel Gubarev,[108] a former member of the Progressive Socialist Party of Ukraine,[109] who was also under arrest on charges of separatism.

[110][111] In response to these actions, acting Ukrainian President Oleksandr Turchynov vowed to launch a major counter-terrorism operation against separatist movements in the country's eastern regions.

[124] Vitaly Yarema said that Russian Special Forces units, including the 45th Parachute Guards Regiment usually stationed near Moscow, were operating on Ukrainian territory in the cities of Kramatorsk and Sloviansk.

[143][144] On the same day, protesters in the city of Donetsk stormed and occupied the chairman of the regional government's private business office and the SBU building, smashing windows and ransacking files as an act of revenge for the clashes in Odesa.

[153] In response, Ukrainian transitional prime minister Arseniy Yatsenyuk referred to Putin's words "hot air", and vowed that the counter-offensive in Donetsk would continue.

[174] A renewed government offensive after the ceasefire broke down resulted in heavy losses for the separatists, forcing them to withdraw from northern Donetsk Oblast, including many cities that had been under their control since April, such as Sloviansk, Druzhkivka, Kostyantynivka, and Kramatorsk.

[184] Another journalist, Evgenii Gapich, a photographer for the Reporter newspaper from Ivano-Frankivsk disappeared in Horlivka, his whereabouts are unknown, but allegedly he has been held in detention by separatist forces in Sloviansk.

They also demanded the stopping of the persecution of former Berkut officers, the disarming of Maidan self-defence units, and the banning of a number of far-right political organizations, like Svoboda and UNA-UNSO.

[131] The monitors met with representatives of a non-governmental organization that said they had been held captive for six hours within the building on 21 April, and that about 100 men in unmarked uniforms with machine guns were present inside it at the time.

[206] A GAZ Tigr heavy armoured vehicle emblazoned with the emblem of the Liberal Democratic Party of Russia was seen parked outside the RSA building on 8 May, along with men in military gear and assault rifles.

[207][208] Whilst speaking to OSCE monitors, the Deputy Governor of Luhansk Oblast said that the "security situation in the region is deteriorating due to activities of the separatists and criminal gangs".

[212][213] A CNN investigation found clear evidence that the detonations 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.

[241] The demonstrators voiced the same concerns about the Ukrainian government's military operations in the East, protesting against Ukraine's efforts to combat separatist insurgents in Donetsk Oblast.

[245] They gathered outside the RSA building with European Union, NATO, and Ukrainian flags, and said that they wanted to prevent the war in the Donbas region from spreading to Kharkiv Oblast.

[194] A hand grenade was thrown from a passing car at a joint police-Maidan self-defence checkpoint outside Odesa on 25 April, injuring seven people, and causing heightened tensions in the region.

[398] The plan called for a week-long ceasefire, starting on 20 June, for the separatists to vacate the buildings they've occupied, for decentralization of power from the central government in Kyiv, and for the protection of Russian-language rights.

The full text of the fifteen points are as follows:[399] Russian president Vladimir Putin offered some support for the plan, but called for Poroshenko to bring the separatists into negotiations.

[356] After a rocket attack that killed nineteen Ukrainian troops, Poroshenko vowed to take revenge on the separatists: "Militants will pay hundreds of their lives for each life of our servicemen.

"[405] Former adviser to the President of Russia Vladimir Putin and a senior fellow at the Cato Institute in Washington, DC, Andrey Illarionov estimates that at least 2,000 Russian intelligence officials were operating in eastern Ukraine.

The file was said to describe the role of an alleged GRU colonel, Igor Ivanovich Strielkov, who had been involved in agitation in the east, including his attempts to suborn Ukrainian soldiers with offers of cash.

[415] The Ukrainian Security Service put out a wanted poster for Strielkov, accusing him of a series of charges, included premeditated murder and organizing mass riots.

A few names of the killed volunteers were established—Sergey Zhdanovich (Сергей Жданович), Yuri Abrosimov (Юрий Абросимов), Aleksey Yurin (Алексей Юрин), Alexandr Efremov (Александр Ефремов), Evgeny Korolenko (Евгений Короленко).

According to the journalists Russian military commissariats (voyenkomat) in Rostov were actively recruiting volunteers for Donbas among former soldiers, especially with specific skills (ATGM, SAM, AGS-17) and those who had previously served in Chechnya and Afghanistan.

[422] On 29 March, Russian political scientist Aleksandr Dugin appeared in a leaked Skype video conference with Kateryna Gubareva, the wife of Donetsk-based separatist Pavel Gubarev.