China lodged a "strong protest" with Japan's embassy in Beijing today after Japanese nationalists landed on an island at the centre of a long-running territorial dispute.
Around a dozen members of a right-wing Japanese group raised national flags on the East China Sea island after sailing there on a 20-boat flotilla carrying activists and MPs.
"Japanese rightwingers illegally violated China's territorial sovereignty," said Foreign Ministry spokesman Qin Gang.
"The Foreign Ministry has already lodged solemn representations and expressed strong protest to the Japanese embassy in China and urged Japan to stop actions which harm China's territorial sovereignty."
Protests against Japan broke out in at least eight Chinese cities today and some saw shops and cars targeted.
In the southern city of Shenzhen, which borders Hong Kong, about 1,000 protesters waved Chinese flags and shouted slogans as they marched on major streets.
Japanese media reported that protesters damaged Japanese businesses and vehicles in Shenzhen and in the eastern city of Hangzhou.
More than 100 people gathered near the complex housing the Japanese consulate in Guangzhou, chanting "Japan get out of the Diaoyu Islands."
Witnesses said demonstrations also took place in Shanghai and the south-western city of Chengdu, where protests shut down Japanese department stores.
Anti-Japan protests also took place in Qingdao, Shenyang and Harbin.
A demonstrator in Hangzhou, which is close to Shanghai, put the number of protesters there at about 1,000.
Nothing will bring back the hundreds of British soldiers killed fighting in Iraq at Tony Blair's behest.
Under a modicum of scrutiny the PM's international 'achievements' quickly unravel
The Con-Dems have had it their way too long. We have to turn this country around