Overseas Tibetan activist groups said security forces fired on Tibetan protesters in southwest China on Monday, killing at least one and injuring others.
Up to several thousand Tibetans in Ganzi prefecture of Sichuan province marched Monday to government offices where security forces opened fire, the Free Tibet group said in an email.
The London-based group said a 49-year-old Tibetan man named Yonten was shot dead and up to 30 others have been shot and wounded in Draggo county.
The claims about Monday's protest could not be independently verified.
A woman who answered the phone at the duty office of the Ganzi public security bureau said she was "not clear" about the situation. "What you should not know, you should not be inquiring about," she said before hanging up.
The unrest comes at a time when tensions are especially high following the self-immolations of at least 16 Buddhist monks, nuns and other Tibetans. Most have chanted for Tibetan freedom and the return of their spiritual leader, the Dalai Lama, who fled to India amid an abortive uprising against Chinese rule in 1959.
Ganzi is a rugged, deeply Buddhist region filled with monasteries and nunneries and has been at the centre of dissent for years. It is also among the traditionally Tibetan areas of Sichuan province and other parts of western China that have been closed to outsiders for months amid a massive security presence.
Many Tibetans resent Beijing's heavy-handed rule and large-scale migration of China's ethnic Han majority to the Himalayan region. While China claims Tibet has been under its rule for centuries, many Tibetans say the region was functionally independent for most of that time.
Another group, the International Campaign for Tibet, said three Tibetans were killed in Draggo on Monday and nine injured when police fired into the crowd.
Kate Saunders, the London-based group's spokeswoman, wrote in an email that other Tibetans were beaten by police and injured. It says leaflets had been distributed saying Tibetans should not celebrate the New Year because of the self-immolations and the overall situation in Tibet. The Tibetan New Year falls on Feb. 22 this year.
China is sensitive to protests by Tibetans because they threaten its control over its western region and may inspire protests elsewhere by Chinese with possible grievances.