After the end of the Vietnamese occupation of Cambodia in 1989 and the withdrawal of the Vietnam People's Army, the Khmer Rouge rebuilt their former bases in the Dângrêk mountain range area, along the border of Cambodia in order to fight against the Kampuchean People's Revolutionary Armed Forces, the armed forces of the State of Cambodia. Anlong Veng, a small town at the foot of these hills, became for a while the main "capital" of the Khmer Rouge. In the 1990s the Khmer Rouge still controlled Anlong Veng, where there was one of the first "killing fields" after the fall of "Democratic Kampuchea".