China has tightened restrictions on travel by foreigners in the Himalayan region of Tibet after five Americans unfurled a banner at the foot of Mount Everest to protest against the staging of the 2008 Olympics in Beijing.

The new rules came into effect after the week-long May Day holiday, an official with the state-run China Travel Service said in Lhasa, the Tibetan capital.

“We can’t let foreign tourists just go anywhere by themselves,” she said. “In the past they could be left alone to travel independently as they wanted for a few days. Now this is not allowed any more.”

Foreigners are also no longer allowed to apply for a permit to enter the region from the office of the Tibetan travel bureau in the southwestern city of Chengdu, from where there are direct flights to Lhasa. All travel must be approved by the head office in Lhasa, which operates under police supervision.

The official said: “Management is tighter because of the Americans on Everest.”

The implementation of the restrictions marks a significant step back towards the early 1990s, when the entire region was effectively closed off to foreigners, except for a tiny number of officially organised tour groups.

That action was prompted by a series of violent demonstrations, led mostly by Tibetan monks, against Chinese rule and by the imposition of martial law after riots swept Lhasa in 1989. There has been a gradual easing of the travel limits over the past few years, although Tibet remains the only region of China for which all foreign tourists must obtain a permit to gain entry.

It had become much simpler and easier to pick up a permit in cities such as Chengdu and Zhongdian near the Tibetan border before boarding a flight or hiring a vehicle, or in Beijing and Golmud, which is on the railway line to Lhasa that opened less than a year ago.

The five Americans were detained last month at the Chinese base camp for Everest after they staged a protest against plans to carry the Olympic torch to the summit of the world’s highest mountain en route to the opening of the Games in Beijing on August 8.

They unfurled a banner reading “One World, One Dream, Free Tibet 2008” – a play on the official slogan of the Games, “One World, One Dream”. The five were detained by police and expelled.

Robert Barnett, a Tibet expert at Columbia University, said: “It may seem strange if five students with a camera can have such an impact on Chinese policy. But, in fact, restrictions have been increasing in Tibet over the last year, with intensified campaigns against the Dalai [Lama], renewed bans on religion for all officials and, recently, public warnings about ‘Western hostile forces’.

“I think that the issue with these US students was not so much that they staged a protest in Tibet, but that they staged it in the middle of a rehearsal for the Olympic ceremonies. The fear of embarrassment during the Olympics seems to be increasingly a paramount concern for PRC [Chinese] officials.”

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