 It was widely alleged that Russian troops, especially those belonging to the MVD, committed numerous and in part systematic acts of torture and summary executions on separatist sympathizers; they were often linked to "zachistka" ("cleansing" raids, affecting entire town districts and villages suspected of harboring "boyeviki" – the separatist fighters).Humanitarian and aid groups chronicled persistent patterns of Russian soldiers killing, raping and looting civilians at random, often in disregard of their nationality.Separatist fighters took hostages on a massive scale, kidnapped or killed Chechens considered to be collaborators, and mistreated civilian captives and federal prisoners of war (especially pilots).