filled with the skulls of the victims.]]The Killing Fields were a number of sites in Cambodia where large numbers of people were killed and buried by the Communist regime Khmer Rouge, which had ruled the country since 1975. The massacres ended in 1979, when Communist Vietnam invaded the country, which at that time was officially called Democratic Kampuchea, and toppled the Khmer Rouge regime. Estimates of the number of dead range from 1.7 to 2.3 million out of a population of around 7 million.