Although all the harbor forts were included in the surrender, General Wainwright made every effort to avoid surrendering the troops in the southern Philippines. He sent an order placing them directly under MacArthur just before surrendering Corregidor. However, the Japanese insisted that all US and Filipino forces in the islands be included, and stated they would not cease offensive operations until that took place. Wainwright believed this meant they might start executing the 10,000 or so prisoners from Corregidor and the other forts, so he ordered the surrender of all forces. The units in the south were in much better positions for both supplies and continued resistance than those at Bataan or Corregidor were, and their commanders believed Wainwright's surrender orders were made under duress. It was not until 9 June that the Japanese accepted that all of the islands had surrendered. Some units never did surrender, and became nuclei for guerrilla operations that continued until the Japanese were mostly killed or captured in early 1945, following MacArthur's return to the Philippines in force in October 1944.