Some people in China share the same ideology as al Qaeda, FBI Director Robert Mueller said on Wednesday, as he warned the group that the United States was on high alert and watching every move by any would-be terrorist.
China, too, was at risk from terror attacks, he said.
"Just because you have not seen substantial terrorist attacks in China does not mean there could not be in the future or in other countries in Asia," Mueller told reporters. He did not elaborate.
Asked if al Qaeda was active in China, which has linked separatists in the restive Xinjiang region to Osama bin Laden's network, Mueller said some individuals in China shared the same ideology as al Qaeda.
"There certainly are individuals in China who could be described as having that same mindset as well as the desire to utilise terrorist acts to further their agenda, whether you would call it al Qaeda or a group loosely affiliated with al Qaeda and al Qaeda's leadership."
China threw its weight behind President George W. Bush's war on terror and in turn won a degree of support for its crackdown on Muslim separatists in the north-west region of Xinjiang. Several such separatists have been captured fighting with the Taleban and al Qaeda in Afghanistan.
Washington agreed to add to its terrorist list one separatist group, the East Turkestan Islamic Movement, which China says trained with, and fought alongside, al Qaeda militants.
US intelligence-sharing with China had proved necessary to preventing terror attacks, said Mueller, who met public and state security, justice and procuratorial officials during two days in Beijing.
Mueller said the Federal Bureau of Investigation was stepping up surveillance before the Athens Olympics and Democratic and Republican party conventions in the United States.
"I think we have to be concerned about the possibility of terrorist attacks between now and the fall," he told reporters.