A 20-year-old Tibetan Buddhist monk has died in detention after he set himself on fire in a town in southwest China that has become a flashpoint for such protests, a US-based rights group said Wednesday.

Lobsang Tsultrim, a monk from the Kirti monastery in Aba town, died on Monday after setting himself alight last week, the International Campaign for Tibet said, citing Tibetan monks now living in exile in India.

The news could not be independently confirmed and local government officials contacted by AFP said they did not know anything about the monk's death.

Witnesses quoted earlier by Radio Free Asia and Free Tibet, another rights group, said Chinese security forces beat Tsultrim and dragged him away after extinguishing the flames on Friday.

The witnesses said the monk had raised his fist, a gesture of defiance used widely by Tibetans who accuse China of abuses, before setting himself alight.

A total of 29 Tibetans, many of them Buddhist monks and nuns, are reported to have set themselves on fire to protest against Chinese rule in Tibetan areas since the start of 2011.

The first was Phuntsog, a young monk from the Kirti monastery whose self-immolation on March 16 last year sparked dramatic protests in Aba, a small town in Sichuan province with a large ethnic Tibetan population.

Many Tibetans in China complain of religious repression as well as a gradual erosion of their culture, which they blame on a growing influx of Han Chinese -- the country's dominant ethnic groups -- in areas where they live.

But China rejects these accusations. Beijing says Tibetans are enjoying better living standards, thanks largely to the huge social and infrastructure investments made by the Chinese.

Beijing has also accused the Dalai Lama, Tibet's spiritual leader, of inciting the self-immolations in a bid to split the vast Himalayan region from the rest of the nation.

In a separate incident, the official Xinhua news agency said late Tuesday that 60 Tibetan monks were ordered to return to their monastery after they staged a 10-minute march in the northwestern province of Gansu.

The brief report gave no further details and a local government official declined to confirm the incident when contacted by AFP.