Free Tibet said Lhamo Kyeb, 27, died Saturday near a monastery in northwestern China's Gansu province. Citing a witness, it said he set himself on fire and ran toward Bhora monastery in Xiahe county and that state security forces standing nearby ran after him and tried to put out the flames.
The witness said Lhamo Kyeb attempted to stop them from extinguishing the fire, forcing them to back away, and then he walked toward the monastery and fell to the ground.
The group said nearly 60 Tibetans have set themselves on fire since March 2011 to protest Chinese rule over the Himalayan region.
Calls to the county government and police rang unanswered Sunday. A man on duty at the prefectural government said he had no information.
"Protests against China's brutal suppression of Tibetan culture and identity have now reached a point where the international community must speak out," Free Tibet director Stephanie Brigden said in a statement. "This Tibet Spring is not going to go away just because international governments choose to ignore it."
Chinese authorities routinely deny Tibetan claims of repression, although they have confirmed some self-immolations and accused supporters of the exiled Tibetan spiritual leader the Dalai Lama of encouraging such acts. The Dalai Lama and representatives of the self-declared Tibetan government-in-exile in India say they oppose all violence.