It began immediately after Sloviansk was seized by the separatist group, the Donetsk People's Republic, which, having received support from Russia, declared itself independent from Ukraine on 7 April.

Following three months of heavy fighting between the Armed Forces of Ukraine and the DPR People's Militia, the Ukrainian government retook the city as the pro-Russia rebels retreated to Donetsk.

On 12 April 2014, as unrest grew in eastern Ukraine following the 2014 Ukrainian revolution, masked men in fatigues, armed with Kalashnikov assault rifles, took over the town and began to fortify it.

[32][33] In response, the Ukrainian Yatsenyuk Government created the first Anti-Terrorist Operations zone (ATO) and launched a series of counter-offensives against the insurgents, resulting in a standoff and violent skirmishes.

"[38] On 20 April, Right Sector was ordered by acting President Oleksandr Turchinov to sabotage an insurgent-controlled television tower, leading to the first combat fatalities.

[citation needed] The leader of the government military operation, General Vasyl Krutov, was attacked by pro-Russian sympathizers after addressing a crowd demonstrating in front of the air base.

[52] Following negotiations, a compromise was reached to return the remaining four BMDs to the Ukrainian military,[53] but an official from the Ministry of Defence announced that the vehicles were still in the hands of the rebels as of 23 April.

According to the International Renaissance Foundation, a Ukrainian NGO, separatist militiamen entered houses inhabited by Romanis, beat the residents, including women and children, and stole their property.

[58] Prime Minister Yatsenyuk said that the government will not tolerate incitement of ethnic hatred and instructed law enforcement agencies to identify those involved in the attacks on Romani.

[60] On 20 April, 20 Right Sector members led by Dmytro Yarosh were covertly sent by acting Ukrainian President Oleksandr Turchynov to destroy the transformer of the Slavyansk television station on Karachun mountain.

[61] Viktoriya Siumar, deputy head of Ukraine's National Security Council, said the shooting was being investigated, but that there were indications that it was "an argument between local criminal groups".

"Armed lawbreakers and saboteurs who are terrorizing the local population around Slaviansk ... have turned to cynical provocation," the SBU security service said in a statement, describing the incident as a "staged attack".

An OSCE assessment released Monday described the situation as "very tense" in Donetsk and as "deteriorating" in Sloviansk, where "the entire town is under the control of armed groups.

[72] A Ukrainian military surveillance plane was damaged by small arms fire as it was on a reconnaissance flight over Sloviansk on 21 April, but safely made an emergency landing.

"[77] On 24 April, Ukrainian troops took control of three checkpoints surrounding the city, and according to the Interior Ministry, five separatists were killed and one police officer wounded in the attacks.

[78] Ukrainian Forces surrounded Sloviansk supported by multiple armoured columns, and warned civilians to stay indoors ahead of a planned offensive on 25 April.

Officials claimed Perepechayenko had been establishing contact with the General staff of the Russian Armed Forces and the GRU, and was arrested at the Donetsk airport while returning from a flight from Moscow.

[84] Residents reported that gunmen from the Donbas militia began extorting shop owners in the local market for "rent" and had begun stealing expensive cars.

[88] A commander at a separatist checkpoint told the Russian News & Information Agency that government forces took control of another of the roadblocks on the outskirts of Sloviansk, as well as the city's television broadcasting centre.

[92] An independent Russian military journalist, Pavel Felgenhauer, said that the effective usage of MANPADS in Ukraine proved not only that the people who used it were specially trained, but that the weaponry was supplied by Russia.

Strelkov, a Donbas Militia leader, told the Russian state media outlet RIA Novosti that "We lost around 10, including peaceful residents, and 20–25 were wounded.

[117] Separatists made repeated attacks on the checkpoints that the Ukrainian forces had set up on roads leading out of Sloviansk, inflicting and suffering casualties without taking the positions.

Separatists and Ukrainian Interior Minister Arsen Avakov both said that a portion of the rebels, including Girkin, military commander of the DPR, were retreating from Sloviansk.

[133] Following the liberation of Sloviansk, in the same weekend (5–6 July), government forces took control of several other towns in northern Donetsk Oblast: Kramatorsk,[128] Druzhkivka, Kostiantynivka[134] and Bakhmut.

Rybak was kidnapped by four pro-Russian militants in camouflage after he took part in a "For a United Ukraine" demonstration near the Horlivka city council building – he was found in the river with a backpack filled with sand around his back and gutted.

In the second part of the recording, Russian Military Intelligence Colonel Strelkov calls Ponomarev to take care of (Rybak's) body because it "is lying here and beginning to smell."

"[173] Ostrovsky says his captors accused him of working for the CIA and FBI, and that during his stay "a dozen other nameless detainees were ferried in and out of the cellar of the Ukraine state security (SBU) building by the pro-Russia militants" and that many had been there for up to two weeks.

When I was asleep on the floor, masked men came to wake me up and tell me how no one would miss me if I died, and then kicked me in the ribs as they left.When asked of his whereabouts during a press conference, self-appointed "people's mayor" Ponomarev said "nobody abducted him, nobody is holding him hostage, he's with us now in at the SBU, preparing material and working.

[179] The Interior Ministry later confirmed that 13 people (seven members from OSCE countries, five Ukrainian military representatives, and the driver) had been taken hostage by pro-Russian militants and held in the SBU building.

The SBU then released what they described as a tapped phone call implicating Russia in the abduction, naming specifically Vladimir Lukin and Igor Girkin.