Chinese police have fired on Tibetan protesters demonstrating after a series of deadly self-immolations by people campaigning against Chinese rule of their Himalayan region, according to a rights group.

A Buddhist monk was shot in the arm after police used tear gas and opened fire during a clash with Tibetans outside a police station in the western province of Sichuan, which borders Tibet, the Britain-based Free Tibet organisation said in a statement.

The group did not say when the violence happened and police in the area could not be reached for comment, Reuters news agency said.

Human-rights activists say China tramples on religious freedom and culture in Tibet, which it has ruled strictly since People's Liberation Army troops "peacefully liberated" the region in 1950.

China rejects such criticism, saying its rule ended serfdom in Tibet and brought development to a backward, poverty-stricken region.

Tibetans in Tibet and in other parts of China have in recent years been protesting against Chinese rule by setting themselves on fire after pouring petrol over themselves.

Fiery protests

In 2012, more than 80 Tibetans staged such fiery protests, according to rights groups. Most of them are believed to have died.

The number of self-immolations has fallen in the past couple of years but a 37-year-old Tibetan monk set himself on fire outside a police station in Sichuan's Dawu county on Tuesday, the third fatal self-immolation in eight days, Free Tibet said.

A 20-year-old woman set herself on fire on Monday in Ngaba county in Sichuan, and last week a 34-year-old men set himself alight in front of a police station in the western province of Gansu, which is also adjacent to Tibet.

The Dalai Lama, Tibetan Buddhists' spiritual leader, fled to India after a failed uprising against Chinese rule in 1959.

He has called the self-immolations "sad" but "understandable".

He says he does not encourage them and has questioned their effectiveness.

China denounces the Dalai Lama as a separatist but he says he is seeking autonomy for Tibet.