History of Japan
Japanese occupation of the Philippines was opposed by large-scale underground and guerrilla activity. The Philippine Army, as well as remnants of the U.S. Army Forces Far East, continued to fight the Japanese in a guerrilla war and was considered an auxiliary unit of the United States Army. Their effectiveness was such that by the end of the war, Japan controlled only twelve of the forty-eight provinces. One element of resistance in the Central Luzon area was furnished by the Hukbalahap, which armed some 30,000 people and extended their control over much of Luzon.