The Hollywood director withdrew from the Games as artistic adviser last Wednesday.

More high-profile protests appear to be in store.

Demonstrations are already being planned for the international leg of the Olympic torch relay in April.

'We will be targeting the various stages of the torch relay for demonstrations and we plan to be in Beijing during the Games for a demonstration,' said Ms Jill Savitt, director of Olympic Dream for Darfur, an organisation set up to pressure China into helping to end the bloodshed in the western Sudanese region.

Indeed, officials from the Beijing Organising Committee for the Games have expressed concerns that the Olympic torch relay is vulnerable, particularly outside China.

China, one of the biggest investors in Sudan and its main arms supplier, has come under international criticism for not doing more to end the civil conflict in Darfur.

Beijing has accused its detractors of 'politicising' the Olympics.

American speedskating champion Joey Cheek dismissed Beijing's charges.

'Countries stage the Games not just because they like sport but because they want to showcase their country, people, culture and political systems. It makes no sense to say it is not political,' he said.

Mr Cheek is a founding member of Team Darfur, a group of around 250 past Olympic athletes and Olympic hopefuls from 42 countries who plan to use the Beijing Games to speak out on Darfur.

The athletes from Team Darfur train in red, green and black sweatbands, and Chinese officials will undoubtedly be looking nervously for any sign of protest when Olympians train and compete in Beijing.

China-born historian Xu Guoqi said: 'The problem is that Beijing hates to be cornered by the critics of China who use the games to score politically or diplomatically.'

And China's critics are numerous.

Britain's Prince Charles last month said he would not attend the Olympics to show support for the Dalai Lama.

Athletes have talked of wearing masks to block out Beijing's choking pollution.

Human rights and media watchdog groups point to the practice of jailing dissidents and journalists on questionable charges.

Other individuals and groups are hoping to shine the spotlight on other controversial policies of the Chinese government.

Mr David Zweig, a China expert at the Hong Kong University of Science and Technology, said Beijing must be ready for the possibility of violent protests, like 'a Tibetan monk setting himself on fire in front of the Beijing Hotel'.

'They are not very adept at handling street protests by foreigners. They've never done it,' he said.

In a sign of its nervousness, Beijing has decided to restrict media access to Tiananmen Square - the heart of a pro-democracy movement crushed by the military in 1989 - especially for television crews.

The Chinese government has admitted the pressure from protest groups is souring Olympic preparations.

China was 'facing accusations from all over the world' that could cause 'problems for the organisation and planning' of the Olympics, the People's Daily, mouthpiece of the Communist Party, said recently.

Mr David Wolf, a Beijing-based media consultant, said that the message China really hopes to convey is: 'Look at us, we're a big friendly panda, not a big scary dragon.'

AGENCE FRANCE-PRESSE, ASSOCIATED PRESS