Like the country's previous colonizers, the Japanese faced strong opposition from the Filipinos. Very early on, Filipinos from all walks of life organized, joined, or supported the guerrilla movement against the Japanese, choosing not to wait for the Americans to continue the resistance. Historians estimate that one in ten guerrillas who served in WWII was female. There might have been more, although many were probably not recognized as officially serving because of their gender and the non-combatant nature of their services. Filipinas took on various roles and tasks in the guerrilla movement. Many of them served as medical aides or nurses for Filipino and American guerrillas and prisoners of war. Women also served as messengers and spies, and as fighting warriors in both guerrilla and Huk battalions.