Thousands of Chinese security personnel fired tear gas today to try to disperse more than 600 monks taking part in a second day of rare street protests in Tibet.
Radio Free Asia said the monks from the Sera Monastery were demanding the release of fellow monks detained for protesting a day earlier.
The Tibet demonstrations follow a string of marches around the world to commemorate the 49th anniversary of an uprising against Chinese rule in the remote, mountainous region that has become a flashpoint for protesters ahead of the Beijing Olympics.
"The police were armed with electric prods. Other uniformed security forces had firearms," a witness said.
On Monday, 300 monks defied authorities by staging a march in the Tibetan capital of Lhasa, which a Chinese Foreign Ministry spokesman described as "an illegal activity that threatened social stability".
Chinese troops invaded Tibet in 1950 and nine years later the Dalai Lama, the spiritual leader of Tibetan Buddhism, fled into exile after a failed revolt against Chinese rule.
Tibet has since become a point of contention between Chinese Communist leaders and those who advocate independence or greater autonomy for the region.