Thats a weird framing. It seems more like an escalation of an already violent clash than Pro Ukrainian protestors burning a building full of Pro russians alive intentionally.

>A 'United Ukraine' rally was attacked by pro-Russian separatists where Stones, petrol bombs and gunfire were exchanged. The pro-Ukraine protesters then moved to dismantle a pro-Russian protest camp in Kulykove Pole, causing some pro-Russian activists to barricade themselves in the nearby Trade Unions House. Shots were fired by both sides, and the pro-Ukraine protesters attempted to storm the building, which caught fire as the two groups threw petrol bombs at each other.

Abhorrent. Not only in the crime but that "although several alleged perpetrators were charged, there has yet to be a trial."

But also, that's forty-eight dead. The fiasco started after "a 'United Ukraine' rally was attacked by pro-Russian separatists." And this was criminality by a protest group (in predominantly pro-Russian territory, no less) not any party claiming to govern Ukraine.