Gary Locke, the US ambassador to China. (Photo/CNS)

The US ambassador to China, Gary Locke, was surrounded by nearly 50 anti-Japanese activists in Beijing on Sept. 18, the 81st anniversary of the Mukden Incident, according to Duowei News, an outlet operated by overseas Chinese.

The Mukden Incident of 1931 was the precursor to the Japanese invasion of northeastern China.

Reports from the Seattle Times said that Locke was surrounded in his vehicle by 50 Chinese protesters in Beijing. Though Locke was unhurt, there was minor damage to his embassy vehicle.

In addition to the prevalent anti-Japanese sentiment sweeping China since Japan's government last week moved to nationalize disputed islands in the East China Sea, there has also been public anger directed against the United States, which turned control of the Diaoyutai (Diaoyu or Senkaku) islands over to Japan when it returned Okinawa in 1972.

After the US ambassador to Libya, Chris Stevens, was killed by an armed group of Islamists in Benghazi on Sept. 11, the safety of US diplomats around the world has become a major concern for the White House. Accordingly, the US embassy in Beijing had asked the Chinese government to give greater protection to American facilities and personnel in the country. The US defense secretary, Leon Panetta, is currently in China, where he has urged restraint to prevent the tensions between China and Japan escalating into armed conflict.