Hundreds of Tibetans demonstrated in northwest China after police beat four people, an exile group and a US broadcaster said, following a recent string of self-immolations in the region.
The London-based Free Tibet said hundreds of people gathered outside police headquarters in Qinghai province's Tongren county Tuesday after police dragged four ethnic Tibetans from a car, beat them and threatened them with guns.
US broadcaster Radio Free Asia quoted witnesses as saying the police appeared to be drunk, and "severely beat" the four men. Tongren government and security officials could not immediately be reached for comment.
The protests followed reports of clashes in the neighbouring province of Sichuan on Monday, where two ethnic Tibetans set themselves on fire on Monday to protest Chinese rule, leading to bloody clashes between residents and police.
"Tensions are high as Tibetans are not prepared to sit back and allow Chinese state oppression to continue unchallenged," said Free Tibet director Stephanie Brigden.
Exile groups say nearly 50 ethnic Tibetans, many of them Buddhist monks and nuns, have set themselves on fire since March 2011 to protest restrictions on their religious freedom.
An influx of Han Chinese, the country's largest ethnic group, to China's vast Tibetan-inhabited areas has also created tensions.
Violent anti-government protests in the Tibetan capital in Lhasa in 2008 later spread to other areas populated by Tibetans, prompting tight security in these regions that has at times led to clashes.
Beijing insists Tibetans are free to practise their religion and have benefited from improved living standards under Chinese rule.