Mass executions have frequently followed violent changes of governments. Due to the institutional and legal vacuum immediately following the fall of a regime and during the transition period, armed forces, revolutionary tribunals, or even mass public rallies, assume the role of imposing 'justice'. Many executions are carried out without any trial. Even when trials are held death sentences are often delivered after brief or summary trials without procedures for safeguarding the rights of the accused, and sentences are often delivered without any legal base. Many of the convicted are executed immediately or within an extremely short period of time after sentencing, in many cases having been given no opportunities for appeal for review of the sentence or for pardon. Killings by or after torture in prison or detention camps are also commonly reported. Those executed are people suspected of their collaboration with the enemy, former government officials, military officers, policemen, supporters and associates of the former regimes, and others suspected of their opposition to the new regime and to the new government's policies. It is not unusual that family members and friends of those accused or executed, including women and children, are also among the victims. Mass executions are often justified by characterizing the victims as traitors, foreign agents, counter-revolutionaries, enemies of the people, etc.