By Sui-Lee Wee and Maxim Duncan
BEIJING (Reuters) - Thousands of Chinese besieged the Japanese embassy in Beijing on Saturday, hurling rocks, eggs and bottles, and protests broke out in other Chinese cities in an angry dispute over a group of remote islands.
Paramilitary police with shields and batons barricaded the embassy, holding back and sometimes fighting with slogan-chanting, flag-waving protesters who at times appeared to be trying to storm the building.
"Return our islands! Japanese devils get out!" some shouted. One held up a sign reading: "For the respect of the motherland, we must go to war with Japan."
Protester Liu Gang, a migrant worker from the southern region of Guangxi, said: "We hate Japan. We've always hated Japan. Japan invaded China and killed a lot of Chinese. We will never forget."
By early evening, police had succeeded in persuading some people to leave. Rings of anti-riot police stood guard in front of the embassy, apparently readying for a long night.
"I think it's time for the Chinese government to get tougher. Look at what the ordinary people feel. The government should respond," said a man who gave his family name as Xue.
"I don't mean war, but tougher action like sanctions. You can see how much Japan depends on our economy. Then don't sell them any rare earths," he said, referring to elements mined in China which are vital to defense, electronics and renewable-energy technologies.
Japan said its foreign minister had cut short a visit to Australia and flown back to Tokyo.
The long-standing territorial dispute escalated dramatically on Friday when China sent six surveillance ships to a group of uninhabited islets in the East China Sea, raising tension between the two countries to its highest level since 2010.
It was responding to Japan's decision on Tuesday to buy the islands, which Tokyo calls the Senkaku and Beijing calls the Diaoyu, from a private Japanese owner after Chinese warnings not to.
Sino-Japanese ties have long been plagued by China's bitter memories of Japan's military aggression in the 1930s and 1940s and present rivalry over resources - the islands are believed to be surrounded by energy-rich waters.
Relations between the two countries, which have extensive business and trade ties, chilled in 2010, after Japan arrested a Chinese trawler captain whose boat collided with Japanese coastguard vessels near the islands.
China's official Xinhua news agency said big anti-Japan protests were also held in the Chinese cities of Xian, Changsha, Nanjing and Qingdao. Japanese media reported attacks on Japanese restaurants and other businesses.
"Armed police and police officers have been dispatched to protest sites to maintain order," Xinhua said.
The microblog of Communist Party mouthpiece the People's Daily called on protesters to behave properly.
"What we should show the world is that as China has peacefully risen so has the quality of its people, and that the government is not lacking in its management of the law," it wrote.
Japan's Kyodo news agency said the demonstrations were the biggest in China since the two countries normalized diplomatic relations in 1972.
Pictures on China's popular Twitter-like Sina Weibo showed protests in provincial cities and pictures of looting of shops and destruction of Japanese cars.
Japanese broadcaster NHK said protesters broke into a dozen factories in the eastern city of Qingdao, including one run by Panasonic. Such attacks prompted Japan's government to complain to China's foreign ministry.
There have been sporadic protests around China throughout the week. Those in Beijing had been small and largely peaceful.
"CHINA WILL NOT SHY AWAY"
The latest dispute flared up last month after Japan detained a group of Chinese activists who had landed on the islands.
China also has similar disputes with neighboring states in southeast Asia over islands in the South China Sea.
Diplomats say Tokyo and Beijing want to keep the row from escalating. That could be made harder by China's impending leadership changes and a looming election in Japan.
China's ruling Communist Party rarely permits street protests. "I think the government is encouraging this," said one protester, who gave his name as Uda Chen.
"They could have stopped all of us approaching when we were at the subway station. The government has taught us to be anti-Japanese at school, so if they want us to stop it would be like slapping their own mouths," he added.
The influential tabloid Global Times, published by the People's Daily, said backing off was not an option for China.
"China should be confident about strategically overwhelming Japan," it wrote, saying Chinese forces should "increase their preparation and intensify their deterrence" against Japan.
"China will not shy away if Japan chooses to resort to its military," the paper added.
(Additional reporting by Chris Buckley, Terril Yue Jones, Lucy Hornby and David Gray in BEIJING, John Ruwitch in SHANGHAI and Yoko Kubota in TOKYO; Writing by Ben Blanchard; Editing by Andrew Roche)