Thousands of people have taken to the streets of the Chinese city of Shanghai in the latest in a series of anti-Japanese demonstrations.
Police made no attempt to stop the demonstrators
Protesters carrying Chinese flags surrounded the Japanese consulate throwing stones and other missiles.
They are angry at Japan's approval of school textbooks which they say play down Japanese wartime atrocities.
The protests were condemned as "extremely regrettable" by the Japanese foreign minister, who is due to visit.
Nobutaka Machimura said he would "strongly protest" against the anti-Japanese protests when he arrives in Beijing on Sunday, in a visit aimed at defusing the tensions.
He called on the Chinese authorities to "take all necessary measures" to protect Japanese people and their interests in China.
The recent protests come despite police warnings against holding rallies.
In Shanghai, police in riot helmets kept the crowd from entering the Japanese consulate, and appealed for calm using loud-hailers.
The protesters damaged about 10 restaurants and bars that serve Japanese customers on Huaihai Road, a major shopping street in the Chinese business capital, the Associated Press news agency reported.
The crowd - many carrying banners and chanting through the streets - targeted businesses with Japanese signs, even though many are Chinese-owned.
In the eastern city of Hangzhou, about 10,000 people are reported to have taken to the streets.
On Friday, the authorities in Beijing issued a statement calling on residents not to participate in any unapproved marches, or to do anything to influence social stability.
Chinese officials are wary of a repeat of last weekend's violent protests in Beijing, which angered Tokyo and led to escalating bilateral tensions.
Japan's decision to approve eight school textbooks - which critics say gloss over the country's actions before and during World War II - triggered the current protests.
Among the issues causing outrage is the description of the Japanese army's massacre in Nanjing, referred to in one of the books as "an incident".
Some 250,000 to 300,000 Chinese people were killed between December 1937 and March 1938 in one of the worst massacres in modern times.
Correspondents said the scale of last week's Beijing disturbances was unusual for China, and indicated tacit official support for the protesters.
In Beijing, a massive security operation is under way to prevent a protest from taking place in Tiananmen Square.
War of words
Hundreds of uniformed police have been seen checking the identities of people trying to get onto the square.
Outside the Japanese embassy too, a massive police presence is in place.
Riot police with helmets and shields line the street, while busloads more are parked in side streets.
Japan has urged its nationals in China to keep a low profile.
The rallies have triggered a war of words between China and Japan, with Tokyo demanding an apology and compensation for the protests, while China told Japan to "face up to history" and admit the suffering caused by its forces before and during the war.
The protests were also directed at Tokyo's bid for a permanent UN Security Council seat.
On Wednesday, Japan further angered China by issuing drilling rights for oil and gas in a disputed area of the East China Sea.
Chinese Foreign Ministry spokesman Qin Gang called the decision a "serious provocation to the rights of China and the norm of international relations".