BEIJING — China has appointed a top anti-terrorism expert as a vice public security minister following a series of alleged plots against this summer's Beijing Olympics, a notice on the ministry's Web site said today.

Yang Huanning has extensive experience in central government bodies dedicated to battling government opponents in the restive western regions of Xinjiang and Tibet, according to his resume posted on official Web sites.

His other portfolios have included managing China's international image, often clouded by charges of human rights abuses and authoritarian policies, along with working with the United Nations Office of Peacekeeping on deployments of Chinese forces.

Beijing has called terrorism the single biggest threat to the games and claims to have foiled multiple plots targeting the event. Yang's appointment also appears to reflect Beijing's desire to paint critics of Tibet and Xinjiang policies as violent terrorists, despite claims from many such groups that they seek only to peacefully protest Chinese policies as a way of furthering dialogue.

Communist officials routinely vilify Tibet's exiled Buddhist leader the Dalai Lama as a separatist, an accusation he denies, and have accused his supporters of orchestrating violent protests this spring to sabotage the Olympics and preparing "suicide squads" to carry out attacks.

On at least three occasions this year, authorities say they foiled plots that targeted the games either directly or indirectly, including alleged attempts to crash an airliner and kidnap athletes and journalists. Evidence provided has been scant.