Police opened fire on Tibetans protesting against religious repression in China on Monday, killing at least one person and injuring more than 30 others, local monks and rights groups said.

Citing a local government statement, the official Xinhua news agency confirmed one protester was killed in Sichuan province's Luhuo county (Dragko or Draggo in Tibetan) in a clash with police, but did not mention shootings.

The demonstration on the first day of the Chinese New Year comes at a tense time in China's Tibetan-inhabited regions, where 16 people have set fire to themselves in less than a year -- including four this month alone.

According to three different monks at Drakgo Monastery -- one of the largest in the area -- thousands of people marched to the local police station on Monday morning to call for religious freedom and to protest local corruption.

"Around 2 pm, the police fired into the crowd from the windows. One person died and 32 were injured, and the crowd dispersed around three hours later," the monks, who would not be named, told AFP.

They relayed each other over the phone to tell the story in halting Mandarin.

Rights groups with contacts in the area and the India-based Tibetan government-in-exile also confirmed the incident took place.

Radio Free Asia, citing Tibetan sources in the region and in exile, including Tibet's government, said the death toll could be as high as six.

RFA quoted the online Tibetan news magazine Tibet Express based in Dharamsala, India, which confirmed the toll of "at least six" killed.

Xinhua had a different version of the incident, saying dozens of people gathered outside a bus station in Luhuo after a man put up posters claiming a monk would set himself on fire there.

"The protest turned violent at around 2 pm, as the crowd began attacking a police station with clubs and stones," it said.

"One protester was killed in the following clash with the police, which also left five officers injured," it added.

Police and the local Communist Party committee in Luhuo said they were unaware of the incident when contacted by AFP.

The London-based Free Tibet and the US-based International Campaign for Tibet (ICT) said Tibetans from nearby counties were reported to be converging on the nearby Dragko Monastery on Monday to join demonstrators.

Free Tibet said the man killed was called Yonten and his body was taken to the monastery, where the injured people had also gathered. One of those hurt was described as having a bullet wound in his stomach.

"Due to fears for their safety, Tibetans who were injured are unable to seek treatment at the local government-run hospital," ICT said.

Both rights groups confirmed the protest came after unknown people posted leaflets in the area that included a declaration by a Tibetan of his or her intention to set fire to themselves.

Aside from religious repression, many Tibetans in China also complain their culture is being eroded by an influx of majority Han Chinese people in areas they live in.

Beijing denies it uses repressive methods against Tibetans, insisting they enjoy freedom of religious belief.

Stephanie Brigden, head of Free Tibet, called on the international community to condemn the incident.

"This is the largest reported shooting of Tibetans since 2008 and demonstrates the deepening crisis in Tibet," she said.

Lhasa, capital of the Tibet autonomous region that neighbours Sichuan, was hit by riots against Chinese rule in March 2008, and unrest subsequently spread to nearby Tibetan-inhabited areas.

Since then, authorities have increased security in these areas and the situation remains tense.

According to ICT, monks, nuns and lay people in Luhuo were fired upon by police in March 2008 when they held a peaceful protest.

In the last reported self-immolation earlier this month in Aba -- another county in Sichuan -- rights groups said police fired on hundreds of locals as they attempted to rescue the burned body from officials.

The government-in-exile said in a statement on its website that it was "deeply aggrieved by the incidents (in Dragko) and condemns the Chinese authorities for resorting to such drastic acts of force and repression."

Beijing blames the Dalai Lama -- who fled Tibet following a failed uprising against Chinese rule in 1959 and is vilified as a "separatist" by Communist authorities -- for much of the unrest.