During the Second World War, Japanese forces occupied Borneo and treated all of the indigenous peoples poorly – massacres of the Malay and Dayak peoples were common, especially among the Dayaks of the Kapit Division. In response, the Dayaks formed a special force to assist the Allied forces. Eleven US airmen and a few dozen Australian special operatives trained a thousand Dayaks from the Kapit Division in guerrilla warfare. This army of tribesmen killed or captured some 1,500 Japanese soldiers and provided the Allies with vital intelligence about Japanese-held oil fields.