Siege of Sloviansk. image - Donbass Crisis mod for Men of War: Assault Squad 2

The Siege of Sloviansk was an operation by the Armed Forces of Ukraine to recapture the city of Sloviansk in Donetsk Oblast from pro-Russian insurgents who had captured it on 12 April 2014. The city was recaptured on 5 July 2014 after shelling from artillery and heavy fighting. The fighting in Sloviansk marked the first major military engagement between pro-Russian separatists and Ukrainian government forces, in the first runoff of battles in 2014.
On 12 April 2014, as unrest grew in eastern Ukraine following the 2014 Ukrainian revolution, masked men in fatigues, armed with Kalashnikov assault rifles, captured the city administration building. These men, who claimed to be pro-Russian fighters under the banner of the Donetsk People's Republic, subsequently gained control of the rest of Sloviansk and began to fortify it. 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. As tensions in the city increased, the insurgents began to take journalists and others captive, instigating a hostage crisis. The Security Service of Ukraine said on 18 April that "Sloviansk remains the hottest point in the region". 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. By June, roughly 40% of the city's population had fled. On 5 July, after the insurgents had retreated to Donetsk City, Ukrainian authorities retook control of the city.