We will take it one section at a time:
"In early 2014, there were clashes between rival groups of protestors in the Ukrainian city of Odesa, during the pro-Russian unrest that followed the Ukrainian Revolution.[21][22] The street clashes were between pro-revolution ('pro-Maidan') protesters and anti-revolution ('anti-Maidan'), pro-Russian protesters. Violence erupted on 2 May, when a 'United Ukraine' rally of about 2,000 was attacked by about 300 pro-Russian separatists.[23] Stones, petrol bombs and gunfire were exchanged. A pro-Russian gunman shot dead a pro-Ukraine protester.[24] Another pro-Ukraine activist and four pro-Russia activists were shot dead in the clashes.[25][26][27][28] The pro-Ukraine group 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 from the building at the pro-Ukraine group,[24] and the pro-Ukrainians attempted to storm the building, which caught fire as the two groups threw petrol bombs at each other.[29][30][31]"