Allied forces did not attempt to retake the islands of Java, Sumatra, Timor, or Bali during the war. Japanese forces on those islands surrendered at the conclusion of World War II. Most of the Japanese military personnel and civilian colonial administrators were repatriated to Japan following the war, except for several hundred who were detained for investigations of war crimes, for which some were later put on trial. About 1,000 Japanese soldiers deserted from their units and assimilated into local communities. Many of these soldiers provided assistance to Indonesian Republican forces during the Indonesian National Revolution.