CHENGDU, CHINA, OCT. 7 -- Chinese authorities cut off telecommunication with Lhasa today and warned foreigners not to travel to Tibet as police tightened security in the Tibetan capital to prevent further anti-Chinese protests.

In another move to isolate Tibet, the Chinese Foreign Ministry told foreign correspondents they must give 10 days notice if they want to travel to Tibet. Pro-independence protests that began last week in the isolated region have presented China with the most serious crisis it has faced there in two decades.

The Foreign Ministry also denounced a U.S. Senate resolution Tuesday that condemned Chinese "human rights violations" in Tibet, saying that it "confounds and confuses right and wrong." Chinese officials have grown strident in their protest against what they describe as foreign interference in China's internal affairs -- interference by the U.S. Congress and by foreign visitors to Lhasa who openly sympathize with Tibet's independence movement.

Western tourists arriving today from Lhasa in Chengdu, the closest Chinese city to Tibet, said that police roused foreigners from their beds in several low-budget hotels in Lhasa around midnight last night and demanded to see their passports.

A specialist on Tibet from Singapore who is living in one of the hotels said the police appeared to have two aims: to intimidate foreigners who appear to advocate Tibet's independence and to check on Tibetan exiles from Nepal and India.

The Dalai Lama, the exiled Tibetan leader whom the Chinese have blamed for the recent rioting in Lhasa, is strongly supported by Tibetan exiles. The Dalai Lama fled Tibet in 1959, when the Chinese suppressed a Tibetan uprising.

Communist China had sent 40,000 troops into Tibet on Oct. 7, 1950, to crush a poorly armed resistance movement.

The police questioned the foreigners during the police raid but made no searches of hotel rooms.

As many as 2,000 foreigners are currently staying in hotels in Lhasa. Many of the westerners sympathize with the Tibetans and their aspirations to shake off Chinese rule.

Witnesses said several foreigners threw stones at police during the anti-Chinese riot on Oct. 1 which left at least six dead from police gunfire and a larger number wounded.

The police recently interrogated two Americans and told them to leave China within 10 days because they attached Tibetan flags to their bags, displaying their support for Tibetan independence.

Many backpackers who come here are attracted to the Wild West atmosphere of Lhasa, where they can mingle with ragged nomads, devout Buddhist pilgrims, tall Khampa tribesmen, and shaven-headed monks, all going about their business in a good-humored way.

Tibetans are an easygoing people and many foreigners find that attribute refreshing and a relief from the restraint many Chinese show. A number of western tourists said that they resent the "hassles" they encounter when dealing with the Chinese and much prefer to deal with the accessible Tibetans.

"The Tibetans are wonderful," said Sonia Pearson, 23, a student of modern languages from London. "They're always laughing. They have a warm sense of humor. They present us with babies to hold."

Another backpacker who arrived today from Lhasa said, "The Tibetans are frightened. When the police show up, the Tibetans move away. . . . The place is swarming with secret police."

Chinese authorities opened Tibet, the fabled roof of the world, to independent travelers only three years ago. Only 2,000 tourists visited Tibet two years ago. This year, as many as 40,000 are expected. The tourist trade brings in up to $20 million a year, which is an enormous sum for China's poorest region.