 However, the largest Chetnik massacres took place in eastern Bosnia where they preceded any significant Ustashe operations.According to Pavlowitch, terror tactics were committed by local commanders of the Chetnik organisation.Mihailović disapproved these acts of ethnic cleansing against civilians, however he failed to take action in stopping these acts of terror, given the lack of command he had over local commanders and the rudimentary methods of communication that existed in the Chetnik command structure.