Protesters have hurled stones, bottles and paint at the Japanese consulate in Shanghai and attacked Japanese businesses as thousands of people staged anti-Japan rallies.
Riot police three-deep linked arms to prevent the rowdy crowd on Saturday from entering the.
A group of protesters began throwing objects including stones, bottles and bags filled with paint towards the building.
Barriers broken
An AFP reporter saw two people break through barriers surrounding the building, but police pulled them down.
Close to the consulate on Xianxia Road, three Japanese businesses and a Japanese restaurant were attacked with bottles and eggs, another AFP reporter said.
Onlookers estimated 5000 to 10,000 people marched along the main Yanan Road towards the consulate, yelling anti-Japanese slogans and calling for Tokyo to adequately apologise for its wartime aggression.
A duty officer at Shanghai public security bureau said the rally had not been approved.
The protests were sparked by the Japanese government's approval of revamped history textbooks that Beijing thought made light of the nation's atrocities in the second world war.
Last weekend, there were violent rallies in Beijing, and the southern cities of Guangzhou and Shenzhen.
Call for calm
Japan and the United States issued urgent alerts on Friday for their citizens to be careful.
Chinese State Councillor Tang Jiaxuan, a former foreign minister, said Japanese leaders' visits to the Yasukuni shrine honouring war dead, including convicted war criminals, were at the heart of the problems.
In a meeting with Toyohiko Yamanouchi, president of Japan's Kyodo News Agency, he described relations to be "at the crossroads".
Japan on Wednesday said it would let its companies drill for oil and gas in the disputed East China Sea. Beijing, which began drilling in 2003, called the move a provocation.
In an effort to salvage ties, Japan's Foreign Minister Nobutaka Machimura is scheduled to arrive in Beijing on Sunday for meetings with China's top leaders.
Protests are expected in other cities including Guangzhou, Shenyang, Chengdu, Hangzhou, Tianjin and Wuhan on Sunday.
PHOTO CAPTION
A protester destroys the Japanese sign board of Japanese restaurant Kissho on Saturday April 16, 2005 in Shanghai, China.
(AP Photo)