Conflict in this theatre began when the Empire of Japan invaded French Indochina in September 1940 and rose to a new level following the Attack on Pearl Harbor, and simultaneous attacks on Hong Kong, the Philippines, Thailand, Singapore and Malaya on 7 and 8 December 1941. The main landing at Singora (now Songkhla) on the east side of the Isthmus of Kra preceded the bombing of Pearl Harbor by several hours.