Tibetans in exile say a teenage nun has set herself on fire in China's southwestern Sichuan province.

Reports say 18-year-old Tenzin Choedron self-immolated Saturday near the Mamae convent, outside the besieged town of Ngaba. Witnesses said she did not die, and was taken away by Chinese authorities.

Her condition is not known.

Tibetan exile groups claim that about 20 people have burned themselves since March of last year to protest the Chinese government's repression of Tibet's culture and religion.

Officials in Beijing have condemned self-immolations as a form of terrorism. They have accused Tibet's exiled leader the Dalai Lama of supporting them.

The Dalai Lama says he is only fighting for Tibet's cultural autonomy. He has not supported the self-immolations, but he has not condemned them either.