Interpol has warned that China must be prepared for a possible Al Qaeda attack on the Beijing Olympics, as well as potentially violent disruption from pro-Tibet protesters.

"We must be prepared for the possibility that Al Qaeda or some other terrorist group will attempt to launch a deadly terrorist attack at these Olympics," Interpol chief Ronald Noble told an international conference on security for the Games in Beijing.

"The threat is compounded by the very nature of the event," the head of the international police organisation, based in the French city of Lyon, told the gathering.

"China will open its doors to hundreds of thousands of foreign visitors and journalists and an audience of billions watching on television. This could provide easy cover for terrorists and ensure any attack during the Olympics would have an immediate global impact."

"There is no doubt that the biggest threat facing the Beijing Olympics is terrorism," China's minister of public security Meng Jianzhu said.

"I hope that all parties will adopt practical and effective measures, strengthen border controls to jointly prevent and suppress international terrorist activities targeting the Games," he said.