Liquidation of political opposition by governments may sometimes mean the killing of tens and hundreds of thousands of people sharing a political or religious belief or belonging to one ethnic group. These purges are more often carried out by security forces, although in some cases the participation of civilians that have been set against the designated victims may be decisive, particularly to establish a mock legitimacy for such an ordeal. Staged incidents, such as encounter killings, fictitious escapes from prison, or alleged resistance to police forces, are other forms of concealing the true nature of these killings.
In Kampuchea, under Pol Pot's rule, 1 million people were killed, often by fellow countrymen. Political mass murders regularly occur in Central America, often under the guise of disappearances.