The three men were shot Tuesday by police who were looking for or had detained another man in connection with a Jan. 25 incident in which protesters tore down a Chinese flag at a police station in a Tibetan area of Qinghai province, according to London-based Free Tibet and Radio Free Asia. Both cited unidentified sources in the area.
Employees who answered the phone at local government and police offices in Pema county and the prefecture where it is located, Golog, said they had not heard of the shootings.
More than two dozen Tibetans have set themselves on fire over the past year to protest what activists say is Beijing's suppression of Tibetan religion and culture. The communist government has blamed supporters of the exiled Tibetan Buddhist spiritual leader the Dalai Lama for encouraging the self-immolations.
The latest protests come at a sensitive time for Tibet and China.
China's national legislature is meeting this week amid heightened security throughout the country. March also is when Tibetans mark significant anniversaries, including that of the unsuccessful 1959 revolt during which the Dalai Lama left for exile in India, and deadly anti-government riots that rocked the Tibetan capital, Lhasa, in 2008.
The head of the Tibetan government-in-exile, Lobsang Sangay, issued a statement Saturday calling on new Chinese leaders due to take power this year to give the region "genuine autonomy" within the framework of the nation's constitution.
"When Tibetans gather peacefully and demand basic rights as outlined in the Chinese constitution, they are arrested, fired upon and killed," the statement said. "We hope that China's upcoming leaders will initiate genuine change, and that they find the wisdom to admit the government's longstanding hardline policy in Tibet has failed."
Free Tibet said the man who was killed this week, identified as Choeri, and the two who were wounded were shot after they went to a police station to object to the arrest of another man. It said that man, Thubwang, was believed to be a leader of the protest.
Radio Free Asia said the three men were shot while trying to protect Thubwang during a police manhunt.
The two wounded men are brothers, identified as Karkho and Jampel Lodroe, Free Tibet said. One was wounded in the arm and the other in the leg, and both were treated at a local hospital, it said.
Tibetans, including a prominent writer in Beijing, have pleaded for an end to the self-immolations, saying they are not helping the cause of Tibetan rights.
On Thursday, poet Tsering Woeser said in an online appeal that she is "grief-stricken" about people who have set themselves on fire. The appeal called on influential Tibetans, including monks and intellectuals, to help end the deadly form of protest.
On Friday, Chinese President Hu Jintao met in Beijing with Tibetan delegates to the legislature and urged them to maintain stability, spread the message of ethnic unity and safeguard the unity of the motherland, the official Xinhua News Agency said. He did not mention the self-immolation protests.
The Dalai Lama has praised the courage of those who engage in self-immolation and has attributed the protests to what he calls China's "cultural genocide" in Tibet. He also says he does not encourage the protests.