Supporters say they are concerned about the young man's health.
But her current condition is still unknown, sources said.
Bapa Phuntsok Wangyal passes away in Bejing at 92 and the Dalai Lama expresses his condolences.
It is the 130th burning protest against Chinese rule.
Authorities have refused requests to move him to a hospital for better care.
Two are held in connection with the painting of independence slogans and mailing of 'anti-China' writings to local officials.
Their protests occurred on the same day in neighboring Chinese provinces.
The protests in Gansu province's Sangchu county are the latest against Chinese state-backed mining in the area.
He had taken part in protests challenging Chinese rule in Tibetan areas.
The independence slogans were written in red paint on boulders in Tibet.
The burning protests occur on the sixth anniversary of the deadly Chinese crackdown on Tibetans in Ngaba.
Security forces march in Lhasa, question Tibetans in Chinese provinces.
He is being held in a cold, dark room and is poorly fed, sources say.
Lobsang Sangay says the younger generation of Tibetans in Tibet 'clearly and loudly demand their identity, freedom and unity.'
Legislators from both sides of the political aisle welcome the Tibetan spiritual leader.
Police had monitored his sharing of politically sensitive information.
He dies on the way to a hospital after being held in custody for only a day.
Customs should be passed along to the next generations, exile leader says.