The guard of honour marches during a flag-raising ceremony held in "September 18" Historical Museum in Shenyang, capital of Northeast China's Liaoning province, Sept 18, 2011. Sirens wailed Sunday morning in cities in northeast China's Liaoning, Jilin and Heilongjiang provinces to observe the 80th anniversary of Japan's invasion. On Sept 18, 1931, Japanese forces attacked the barracks of Chinese troops in Shenyang. The move marked the beginning of the Japanese invasion and occupation that lasted 14 years.[Photo/Xinhua]