An 18-year-old Tibetan Buddhist nun is reported to have died after setting herself on fire in China's southwestern Sichuan province.

Tibetan activists identified the nun as Tenzin Choedon, who was quickly taken away by Chinese security forces. Her nunnery, located in Aba county, east of Tibet, was immediately sealed off.

The nun's death brings the number of Tibetans who have died from self-immolation in the past year to more than one dozen.

Recent months have seen an upsurge in anti-Chinese protests in Tibetan areas of China, the worst since 2008.

The Chinese government accuses the Dalai Lama, Tibet's exiled spiritual leader, and overseas organizations such as the London-based Free Tibet movement for fomenting the unrest.

China has ruled Tibet since 1950.