Since the fall of Singapore, the Japanese sent several thousand of British and Australian prisoners of war to camps in Borneo such as Batu Lintang camp. From the Sandakan camp site, only six of some 2,500 prisoners survived after they were forced to march in an event known as the Sandakan Death March. In addition, of the total of 17,488 Javanese labourers brought in by the Japanese during the occupation, only 1,500 survived mainly due to starvation, harsh working conditions and maltreatment. The Dayak and other indigenous people played a role in guerrilla warfare against the occupying forces, particularly in the Kapit Division. They temporarily revived headhunting of Japanese toward the end of the war, with Allied Z Special Unit provided assistance to them. Australia contributed significantly to the liberation of Borneo. The Australian Imperial Force was sent to Borneo to fight off the Japanese. Together with other Allies, the island was completely liberated in 1945.