Both perpetrators and masterminds behind the clashes outside the walls of the Ukrainian Verkhovna Rada on August 31, which claimed the lives of three National Guard soldiers, should be punished, President Petro Poroshenko has said.

"No doubt, there is the responsibility of the perpetrators who threw grenades and firecrackers with nails, screws and other shrapnel, and there is the responsibility of the leaders of political forces, who organized, assisted and issued commands, and coordinated the presence of armed people there. There is the responsibility of the financing oligarchs who also took part in it," Poroshenko said in an interview on the Channel 5 television on Sunday evening.