after the august 1945 surrender of japan in the pacific war, allied commander in southeast asia louis mountbatten following negotiations with a japanese delegation tasked existing japanese forces in southeast asia to maintain law and order until allied forces could arrive. by september 1945, many japanese units in java had disarmed, surrendering weapons and ammunition to indonesian nationalists. the city of semarang in central java was also by then largely controlled by indonesian authorities in form of the "badan keamanan rakyat" (bkr), with the local "kenpeitai" having been largely disarmed. raf wing commander t.s. tull arrived in central java on 18 september as part of a recovery allied prisoners of war and internee (rapwi) delegation and concluded that japanese cooperation was vital to repatriating allied prisoners.