Sitting in a teahouse in Chengdu's Tibetan quarter, a nervous young monk spoke of how police arrests of innocent people were adding to the climate of fear in China's Tibetan-inhabited regions.

The Lama temple where the monk lives is a 15-hour drive away, high up on the Tibetan plateau in the southwestern province of Sichuan where rights groups say police have fired on demonstrators three times in the past week, killing at least three and leaving dozens wounded.

The 28-year-old, whose name is being withheld to protect him, was not in the areas where the killings took place and told AFP he learned of the shootings through friends.

But drinking milky Tibetan tea and fingering his prayer beads in the teahouse in Sichuan's capital Chengdu, his nervousness betrayed the tense atmosphere in the restive province where a series of self-immolations had already prompted an increase in security.

"They have arrested many people who have done nothing. This has only increased the discontent," he said.

According to Tibetan exiles living in India, at least 136 Tibetans have been arrested or disappeared into police custody this month in Sichuan, which borders Tibet.

"We love peace and we hope for peace," the monk said, adding that mandatory "re-education" classes, often dominated by political and patriotic indoctrination, have been forced on his monastery.

The government has said two Tibetans were killed in clashes in the towns of Seda and Luhuo, with one shot dead by police who responded after a violent mob attacked them.

Another Tibeten protester was shot dead in Rangtang county, rights groups said Friday, but a local government official denied there had been a protest.

The unrest comes at a time of growing tensions in Tibetan-inhabited areas, where at least 16 people in less than a year -- four this month alone -- have set themselves on fire to protest against China's rule.

Outside the teahouse, dozens of uniformed and plain clothes police were out on the streets, seeking to stop any conversations with locals.

Chinese authorities have stopped foreign journalists from going to the affected areas, making independent attempts to verify the situation there nearly impossible.

Several hours earlier, police detained two AFP journalists while trying to enter a town in Aba prefecture, where much of the recent anti-Chinese unrest has occurred.

"The region is inaccessible due to the mudslides," police told the journalists before escorting them on the six-hour drive back to Chengdu.

The day before, the two journalists were stopped on another road leading into Tibetan-inhabited areas and forced to turn back "because of snow".

In Chengdu, a huge modern city in the throes of an economic boom, Tibetans are a small minority among the population of 14 million, most of whom are ethnic Han Chinese.

But relations between the two communities are not openly discordant.

Suo Lang Wa Zhang, a 19-year-old Tibetan who lives in Chengdu, said she has many Han Chinese friends and does not rule out the possibility she could one day marry a non-Tibetan.

"Tibetans in rural areas do not have the same perspective on life that Tibetans in the cities have," the young woman, who moved from Tibet, said.

She said she never wanted to see a repeat of the violent anti-Chinese riots that started in the Tibetan capital of Lhasa in 2008 and spread to other regions.

Her friend San Dong Jin Mei, 20, a student in a business school, who unlike many older Tibetans speaks fluent Mandarin, appeared equally integrated.

"I hope to live a happy life and improve my standard of living," she said.

The two women hope to one day return to Lhasa, a two-day train ride away.

But in Lhasa the police presence has also been stepped up in recent days, according to Free Tibet, a rights group that regularly denounces "cultural genocide" and suppression of civil liberties in China's Tibetan-inhabited regions.

"Chinese authorities are using intimidation and surveillance of ordinary Tibetans to instill a culture of fear and stop people from speaking out," said the group's director, Stephanie Brigden.

Communist authorities in Beijing routinely deny such accusations, insisting that Tibetans enjoy religious freedom, while enormous efforts have been made to improve their well-being.

They blame the Dalai Lama -- Tibet's spiritual leader who fled China for India in 1959 after a failed uprising against Chinese rule -- for fomenting the unrest and trying to split Tibet from the rest of China, a claim he denies.