In a sign of Chinese anger at a series of demonstrations by pro-Tibet activists during the Olympics, Beijing police have taken the rare step of detaining six foreigners for ten days.

Administrative punishments are rarely enforced against foreigners whose offences are not deemed serious enough to constitute a crime. The authorities normally prefer to throw people out of the country.

However, the city police said that the six, who were not fully identified, had been ordered to serve ten days in detention for “upsetting public order”.

On August 4 two activists, including a Briton, climbed up two lighting pylons near the Bird's Nest National Stadium to demand independence for Tibet.

Since then China has deported several more protesters from the Students for a Free Tibet group, which said it believed that the six detained for ten days were American pro-Tibet activists arrested by police in Beijing on Tuesday.

Lhadon Tethong, the director of the group, said: “These young men were in Beijing to amplify Tibetan voices calling for freedom and human rights and the right of all people to freedom of expression. They are no more guilty of a crime than Tibetans or Chinese who speak out for justice.”

The US Embassy issued a statement of concern about the detentions. It said: “We call on China to respect the fundamental and universally recognised right of all persons to peacefully express their views, including Chinese citizens, and we urge the Chinese to put their best face forward during these Olympic Games.”

Among the six detained on Tuesday was James Powderley, an American artist, who planned to project a giant laser beam on to a Beijing building with a message in support of a free Tibet.

Early yesterday police arrested Mandie McKeown, 41, a Briton from Briston, Norfolk, with two Americans and a Tibetan-German as they tried to stage a protest near the Olympic Games venues.

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