A group of unidentified individuals has attempted to rush into the U.S. and Japanese Consulates in northeastern China. Some were caught by the police before they entered the diplomatic compounds, but some succeeded.

A spokesman for the U.S. Embassy in Beijing said two intruders scaled the wall and entered the American Consulate General in the northeastern city of Shenyang Wednesday afternoon.

A Japanese Embassy official in Beijing confirms that, at the same time, several people tried unsuccessfully to enter the Japanese Consulate General in Shenyang, several hundred kilometers from China's border with North Korea. He said Chinese police detained them all.

The identity of the intruders has not been disclosed, but China has been on the alert for North Koreans seeking political asylum at Western embassies in recent months. Beijing is North Korea's main ally, and refuses to recognize the refugee status of North Koreans illegally crossing the border to China.

In March, 25 North Koreans rushed into the Spanish Embassy in Beijing and demanded asylum. A day later, they were sent to South Korea via the Philippines.

Since then, Chinese police have stepped up security in Beijing's diplomatic districts by blocking off roads, assigning more guards to watch embassy buildings and attaching barbed wire to perimeter walls.

Aid organizations say tens of thousands of North Korean refugees have fled to neighboring China's northeastern regions to escape famine and repression at home.