Following the defeats in Papua and Guadalcanal the Japanese withdrew to a defensive perimeter in the Territory of New Guinea. In order to secure their important bases at Lae and Salamaua they attempted to capture Wau in January 1943. Reinforcements were flown into the town and defeated the Japanese force in its outskirts following heavy fighting. The Japanese force began to withdraw towards the coast on 4 February. Following their defeat at Wau the Japanese attempted to reinforce Lae in preparation for an expected Allied offensive in the area. This ended in disaster when, during the Battle of the Bismarck Sea, a troop convoy was destroyed by USAAF and RAAF aircraft from the US Fifth Air Force and No. 9 Operational Group RAAF with the loss of about 3,000 troops.