Pol Pot was the leader of the Khmer Rouge and the Prime Minister of Cambodia from 1976 to 1979, having been de facto leader since mid-1975. During his time in power Pol Pot imposed an extreme version of agrarian communism where all city dwellers were relocated to the countryside to work in collective farms and forced labour projects. The combined effect of slave labour, malnutrition, poor medical care and executions is estimated to have killed around 2 million Cambodians (approximately one third of the population). His regime achieved special notoriety for singling out all intellectuals and other “bourgeois enemies” for murder. The Khmer Rouge committed mass executions in sites known as the Killing Fields. The executed were buried in mass graves. In order to save ammunition, executions were often carried out using hammers, axe handles, spades or sharpened bamboo sticks.