A young Tibetan man died and two others were injured in a shooting at a police station in western China, a campaign group has said.
The three had gone to the building in Golog Tibetan autonomous prefecture in Qinghai to complain about the arrest of another man for taking part in a mass protest in January, Free Tibet said.
It added that it was unclear what had happened inside the station on Friday before security forces opened fire, killing Choeri, 28, and injuring brothers Jamphal Lobdu and Karkho, both in their early 20s. They were being treated in hospital for gunshot wounds.
The Guardian was unable to contact the police station in Tagkhar township, known in Chinese as Daka, where the incident is said to have taken place. Calls to the authorities there, and to Pema county – known in Chinese as Banma – and Golog prefecture police and government officials rang unanswered.
Free Tibet said the men had objected to the arrest of a Tibetan called Thubwang for his part in a protest in Tagkhar township on 25 January, in which local residents marched to the government offices and pulled down a Chinese flag.
Some were arrested and the government offered a reward of up to 20,000 yuan for information on the whereabouts of Thubwang, believing he had led the protest, Free Tibet said. It added that another protest had taken place in the neighbouring Wangri township the next day, with protesters carrying portraits of the Dalai Lama and burning the Chinese flag.
Five of the six people who were arrested were unaccounted for, it said. Exiles and campaign groups accused Chinese security forces of killing Tibetans by firing indiscriminately into crowds after protests broke out in January, prompting the US to express grave concern. China's state media later acknowledged deaths, but said security forces had acted in self defence. Tibetan areas have seen the worst unrest since 2008 this year, with several protests and a spate of self-immolations, mostly in Sichuan province.
Earlier on Friday the Associated Press reported that a prominent Tibetan poet under house arrest in Beijing had issued a plea for an end to self-immolations. Tsering Woeser said in online appeal posted on Thursday that she was grief-stricken by the cases and called on influential Tibetans to help halt them.
China has blamed outside groups for orchestrating the self-immolations, and has sought to portray those involved as criminal or having "a bad reputation". Beijing has also accused the Dalai Lama of encouraging the acts. He has spoken of the courage of self-immolations as well as his concern, blaming China's religious and cultural controls.
Woeser is well known for her outspokenness on one of China's most sensitive issues and has posted repeatedly about self-immolations on her blog. Her home is guarded by security officers who say she must request permission to go out and who prevented her from receiving a cultural award at the Dutch ambassador's residence in Beijing last week. Dissidents, activists and others are often put under strict controls while China's annual political meetings are taking place.
The appeal was signed by Woeser, Gade Tsering, another China-based Tibetan poet, and Arjia Lobsang Tupten, a Tibetan Buddhist teacher living in exile in the US. "Tibetans must cherish life and live with resilience. Regardless of the magnitude of oppression, our life is important, and we have to cherish it," they said.
"Staying alive allows us to gather the strength as drops of water to form a great ocean. It depends on thousands and more living Tibetans to pass on our nation's spirit and blood!"