A Chinese protester hurls stones at the Japanese embassy in Beijing. (Reuters)

Beijing, April 9 (Reuters): Thousands of Chinese smashed windows and threw rocks at the Japanese embassy and ambassador's residence in Beijing today in a protest against Japan's wartime past and its bid for a UN Security Council seat.

Protesters pushed their way through a paramilitary police cordon to the gates of the ambassador's residence, throwing stones and water bottles and shouting: 'Japanese pig come out'.

Some 500 paramilitary police holding plastic shields raced into the compound and barricaded the gates. 'Chinese people shouldn't protect Japanese,' the protesters shouted.

Many Chinese harbour deep resentment of Japan's wartime aggression and anti-Japanese sentiment has been running high in China since Tuesday when Japan approved a textbook critics say whitewashes wartime atrocities. Demonstrators, who said they had been organised mostly through e-mail and instant messaging, had been marching peacefully under heavy police guard.

One group began throwing bottles and stones when they passed a Japanese restaurant, smashing windows with tiles they had ripped from its roof before police stopped them. A second restaurant was targeted later in the evening, with rocks thrown through the window, terrifying kimono-clad waitresses.

'We are all Chinese in here and were just minding our own business,' one said after the attack. 'This is terrifying.' Protesters also attacked a Bank of Tokyo-Mitsubishi branch and smashed windows before police moved in.

Another group outside the embassy in southeast Beijing threw stones and plastic water bottles smashing windows in the compound. Some demonstrators scuffled with police.

The violence prompted an official protest in Tokyo by Japanese vice-foreign minister Shotaro Yachi who asked Chinese minister to Japan Cheng Yonghua to strengthen security.