Fresh wave of anti-Japan demonstrations in China on 81st anniversary of Japanese invasion (AP) BEIJING - The 81st anniversary of a Japanese invasion brought a fresh wave of anti-Japan demonstrations in China on Tuesday, with thousands of protesters venting anger over the colonial past and a current dispute involving contested islands in the East China Sea. Outside the Japanese Embassy in Beijing, thousands shouted patriotic slogans and demanded boycotts of Japanese goods. Some threw apples, water bottles and eggs at the embassy, which was heavily guarded by three layers of paramilitary police and metal barricades. Video: China's anti-Japanese rallies turn violent 6 Chinese boats near disputed islands China send patrol boats to disputed islands Japan's Kyodo news agency reported that protesters were throwing bricks and rocks at the Japanese consulate in Shenyang in China's northeast. Similar protests took place in Guangzhou, Wenzhou, Shanghai and other Chinese cities as the country marked the anniversary of a 1931 incident that Japan used as a pretext to invade Manchuria before World War II. In many provinces, including Liaoning, Gansu, Yunnan, Sichuan and Anhui, local governments sounded sirens at 9:18 am to mark the Sept. 18 anniversary, the official China News Service reported. Many China-based Japanese businesses were shut Tuesday as a precaution, after several days in which anger over the island dispute produced occasional outbreaks of violence, including the torching and looting of Japanese-invested factories and shops. Tensions have been growing for months in the dispute over ownership of East China Sea islands called the Senkaku in Japan and Diaoyu in China. The disagreement came to a head last week when the Japanese government said it was purchasing some of the islands from their private owner to thwart a Japanese politician's plans to buy and develop them. Protests since then have been the largest anti-Japanese demonstrations since 2005, reflecting ever-present anger toward Tokyo that periodically bursts to the surface. China's authoritarian government rarely allows protests, and the wave of anti-Japanese demonstrations clearly received a degree of official approval. In Beijing, streams of people marched past the embassy in orderly groups of about 150 people, herded by police who urged them to remain calm and peaceful. Some toted posters of Chairman Mao Zedong, and many shouted slogans such as: "United, Love China, Never forget our national shame." Sun Chao, a 26-year-old employee for a Beijing tutoring company, said he was given the day off and came to demonstrate with about a dozen other friends and colleagues. He spent around 150 yuan (US$24) on apples and bottled water that he was handing out to others on the demonstration route and encouraging people to hurl them at the embassy. "I want to knock down the Japanese national flag," Sun said. Wang Guoming, a 38-year-old retired soldier and seller of construction materials, said he came to Beijing from his hometown of Linfen in Shanxi province to vent his frustration. "I came here so our islands will not be invaded by Japan," said Wang. We believe we need to declare war on them because the Japanese devils are too evil. Down with little Japan!