Following the attack on Pearl Harbor, the Japanese launched offensives against Allied forces in East and Southeast Asia, with simultaneous attacks in British Hong Kong, British Malaya and the Philippines. Hong Kong surrendered to the Japanese on December 25. In Malaya the Japanese overwhelmed an Allied army composed of British, Indian, Australian and Malay forces. The Japanese were quickly able to advance down the Malayan Peninsula, forcing the Allied forces to retreat towards Singapore. The Allies lacked aircover and tanks; the Japanese had complete air superiority. The sinking of HMS "Prince of Wales" and HMS "Repulse" on December 10, 1941, led to the east coast of Malaya being exposed to Japanese landings and the elimination of British naval power in the area. By the end of January 1942, the last Allied forces crossed the strait of Johore and into Singapore.