China said Tuesday it would "resolutely crack down" on any attempts to instigate violence in Tibetan-inhabited areas, where authorities have launched a deadly clampdown on protesters.

At least two people were killed last month in clashes between police and locals in the southwestern province of Sichuan, which has big populations of ethnic Tibetans, many of whom complain of oppression under Chinese rule.

"The Chinese government will resolutely crack down on any attempt to incite violence, disrupt national unity and territorial integrity in accordance with law," foreign ministry spokesman Liu Weimin said.

The unrest in Sichuan -- which borders the Tibet autonomous region -- comes at a time of rising tensions in Tibetan-inhabited areas, where rights groups say at least 19 monks and nuns have set themselves alight in less than a year.

Exile group Free Tibet and US-based broadcaster RFA reported that three self-immolations happened in a remote village of Sichuan on Friday, but local authorities quoted in the official Global Times newspaper denied this.

On Monday, the Tibetan government-in-exile said the wave of self-immolations was a desperate response to "new levels" of Chinese persecution and urged the international community to engage with Beijing to prevent further violence.

Authorities have launched a huge clampdown on Tibetan-inhabited areas, increasing surveillance of monasteries and setting up more road blocks.

In a statement posted on its website Monday, Tibet's government said any official found failing in his or her "duty" of maintaining stability "must be fired on the spot and will be subject to disciplinary penalties".

China has accused overseas organisations pro independence for Tibet of distorting facts about what happened in Sichuan, and has blamed the Dalai Lama -- Tibet's exiled spiritual leader -- of fomenting Tibetan unrest.

"We believe the series of incidents are obviously masterminded and incited by someone behind the scenes," Liu said.

Tibetans have long chafed at China's rule over the vast Tibetan plateau, accusing Beijing of curbing religious freedoms and eroding their culture and language, and these tensions have intensified over the past year.

Beijing insists that Tibetans enjoy religious freedom and have benefited from improved living standards brought on by China's economic expansion.