In Cambodia, a genocide was carried out by the Khmer Rouge (KR) regime led by Pol Pot between 1975 and 1979 in which an estimated one and a half to three million people died. The KR had planned to create a form of agrarian socialism which was founded on the ideals of Stalinism and Maoism. The KR policies of forced relocation of the population from urban centres, torture, mass executions, use of forced labor, and malnutrition led to the deaths of an estimated 25 percent of the total population ( around 2 million people ). The genocide was ended following the Vietnamese invasion of Cambodia. Up to 20,000 mass graves, known as the Killing Fields, have been uncovered.One KR leader said, it was for the ""purification of the populace"" that the killings began. On 2 January 2001 the Cambodian government passed legislation to try a limited number of the KR leadership. Trials began on 17 February 2009. On 7 August 2014, Nuon Chea and Khieu Samphan were convicted and received life sentences for crimes against humanity during the genocide.