During World War II, the town was occupied by Axis troops and was included into the Pavelić's Independent State of Croatia (NDH). The fascist Ustashe regime committed the Genocide of the Serbs and the Holocaust. Between 29 and 37 July 1941, 280 Serbs were killed and thrown into pits near Kostajnica. The town was bombed by American forces on May 30, 1944.