BEIJING (AP) _ Police fired tear gas Monday on thousands of Tibetans who stoned Chinese- owned shops and a police station in the capital of Lhasa, a London-based human rights group said.

The Tibetan Information Network, citing accounts by foreigners, said 2,000 to 3,000 Tibetans took part in the protest over taxes. It said there were reports that one person was killed.

China's official news media did not mention the protest, and efforts to reach government offices in Lhasa were unsuccessful. The network said its information came from foreigners contacted in Lhasa, whom it did not identify.

The exact reason for the protest was not immediately known.

Many Tibetans resent the large numbers of Chinese settlers in Tibet, who live mainly in separate neighborhoods of Lhasa and other towns. The network said tensions have recently risen because of an increase in migrant Chinese traders.

The unrest would be the worst outbreak of violence in Tibet since 1989, when riots led to the imposition of martial law for more than year. Dozens of small protests occur every year, most demanding independence from China.

Monday's unrest came one day after the 42nd anniversary of what China celebrates as the ''peaceful liberation'' of Tibet, when a Tibetan delegation signed an agreement accepting Chinese Communist rule.

A team of European diplomats ended a weeklong visit Sunday to Tibet, where they criticized China for human rights violations.

Several groups reported earlier that police had rounded up more than 100 suspected dissidents before the visit to head off protests. The delegation said it was told the arrests were for security violations.

It was not clear if the protest was related to the visit.