By the time authorities encountered the scenes of rioting, citizens began firing weapons at officers, with the ensuing firefights resulting in many bystanders being killed by "bullets from army troops and from sniping protesters." In many poor areas, citizens destroyed their own local commercial facilities, with food markets so damaged that their food distribution system was ruined. Much of the rioters destroyed properties indiscriminately, with no motives related to initial protests. According to Amnesty International, tactics used by security forces included "disappearances," the use of torture, and extrajudicial killings. As part of the government's security forces, members of Hugo Chávez's MBR-200 allegedly participated in the crackdown. Chávez himself was sick that day with measles. As tensions eased, troops began to sweep through neighborhoods collecting appliances and cash registers and informing citizens that if they provided a certificate of purchase, the items would be returned.