U.S. diplomats say that Chinese police have warned luxury hotels in China of possible terrorist attacks sometime next week. The warning Wednesday comes as preparations for President Bush's visit to Beijing later this month are under way.

A technician operates the latest model of anti-terrorism/anti-bomb robot at Shanghai International Industry Fair Friday Nov. 4, 2005 in Shanghai

The U.S. Embassy says the Chinese police warning was specific: Islamic extremists are planning to attack five and four-star hotels in China "sometime over the course of next week". The embassy advised Americans staying at luxury hotels to remain vigilant and to exercise caution.

The warning comes as Chinese and U.S. officials are preparing for President Bush's November 19 arrival in Beijing. A host of U.S. officials including U.S. Trade Representative Rob Portman, California Governor Arnold Schwarzenegger and former President George Bush, the father of the current president, also are visiting Beijing next week.

There are few known Islamic militant groups operating in China. However, China's northwestern frontier region is home to minority Muslim groups such as the Uighurs. China considers one Uighur group, the East Turkestan Islamic Movement, to be engaged in terrorist activities.

Moreover, several Uighurs fought with the Taleban in Afghanistan and are now in U.S. custody at Guantanamo Bay, Cuba. "China could be vulnerable to terror activities," said Li Nan, a Chinese security expert at the Institute of Defense and Strategic Studies in Singapore. "For instance, Chinese policies in the western part of China like in the Xinjiang Uighur Autonomous Region were pretty heavy-handed."

That treatment might provoke militants to act, but Mr. Li says China has been effective in curbing the groups' activities through security cooperation with neighboring countries like Pakistan and Central Asian states. "China has been trying to contain or to eliminate the safe haven for Uighur separatists operating on the border of Xinjiang and some Central Asian states. About five or six years ago you still read stories about bombings of buses in Wuhan, in Beijing, but for the past few years, you don't read these stories," he said. "In a sense that's one of the indicators government has been relatively successfully in reducing incidence."

The U.S. Embassy said Chinese authorities have made assurances that they are taking appropriate security measures and are investigating the threat. But the Chinese government has not made any formal comment about the matter.

While the United States has frequently issued terror warnings regarding Indonesia in the past few years because of attacks by Islamic militants on Western targets, such a warning about China is rare.

Several luxury hotels in Beijing contacted by VOA late Wednesday said they were not aware of the terror warning. Regional security authorities have been on alert ahead of high-profile international meetings in Asia.

South Korea is hosting the 21-member Asia Pacific Economic Cooperation summit next week, which President Bush, Chinese President Hu Jintao and other Pacific Rim leaders will attend. Next month, international trade ministers will gather in Hong Kong for the World Trade Organization meeting.