Since the Japanese invasion of Manchuria in 1931 followed by the Japanese attack of Shanghai in 1932, there had been ongoing armed conflicts between China and Japan without an official declaration of war. These conflicts finally escalated in July 1937, when the Marco Polo Bridge Incident triggered the full advance from Japan. Dogged Chinese resistance at Shanghai was aimed at stalling Japanese advance, giving much needed time for the Chinese government to move vital industries to the interior, while at the same time attempting to bring sympathetic Western powers to China's side. During the fierce three-month battle, Chinese and Japanese troops fought in downtown Shanghai, in the outlying towns, and on the beaches of the Yangtze River and Hangzhou Bay, where the Japanese had made amphibious landings.