How old were the actors in The Killing Fields (1984)?

New York Times reporter Sydney Schanberg is on assignment covering the Cambodian Civil War, with the help of local interpreter Dith Pran and American photojournalist Al Rockoff. When the U.S. Army pulls out amid escalating violence, Schanberg makes exit arrangements for Pran and his family. Pran, however, tells Schanberg he intends to stay in Cambodia to help cover the unfolding story — a decision he may regret as the Khmer Rouge rebels move in.