Six Tibetans have set themselves on fire in China in the last two days in an escalating wave of protests as the country's leaders gather for a once-a-decade power transition, exile leaders said Thursday.

An 18-year-old man self-immolated on Thursday outside a monastery in Huangnan prefecture in Qinghai province where a 23-year-old woman also died after setting herself alight on Wednesday, the India-based exile government announced.

A trio of monks aged 16 or under also set themselves alight on Wednesday in Aba County in Sichuan province, with one dying of his injuries, while another burning was confirmed in the Tibetan Autonomous Region on the same day.

Self-immolations to protest Chinese rule in Tibet have occurred regularly since March 2011, but Wednesday marked the first time such a large number have happened on the same day. Three are dead in the latest cases.

"We firmly believe that an end to repression will effectively end the cycle of self-immolations," the exile government's premier Lobsang Sangay said in a message to China's incoming leadership.

A total of 69 Tibetans have set themselves on fire since February 2009, of which 54 have died, according to the government in exile, which has been based in India since Tibetan spiritual leader the Dalai Lama fled Tibet in 1959.

In Beijing on Thursday, China's Communist Party opened a week-long congress that is expected to end with the transitioning of power to Vice President Xi Jinping, who will govern for the coming decade.

China blames what it calls the "Dalai clique" for fomenting unrest in Tibet and orchestrating the self-immolations.

Stephanie Brigden, director of the Free Tibet campaign group, said the spate of protests were "aimed at sending the next generation of China's unelected regime a clear signal that Tibetans will continue to fight for their freedom".

The man who set himself alight on Thursday, dying instantly, was named as Jinpa Gyatso by the government in exile. Over 6,000 Tibetans attended his funeral, a statement received by AFP said.

It is difficult for the media to verify reports of self-immolations because independent journalists are prevented from travelling to Tibetan areas.

The protests have divided exiled Tibetans with some seeing them as a legitimate protest while others worry they contravene Buddhist beliefs in the sanctity of life.

Many gathered for a candle-lit prayer vigil in Dharamshala, home to about 10,000 exiled Tibetans, on Thursday in front of a large poster bearing the faces of those who have self-immolated.

The government in exile, which is not recognised by any foreign state, is looking for cause for optimism from Xi's leadership, the 59-year-old son of a Communist revolutionary.

Xi's father, Xi Zhongxun, met and came to know the Dalai Lama in Beijing in the early 1950s, before the Tibetan spiritual leader fled after a failed uprising.

He later became a liberal vice premier seen as sympathetic towards minorities, and Tibetan exiles hope that such thinking may have passed down a generation.

Xi junior's true political leanings are largely unknown, though he has expressed the government's routine disdain for the Dalai Lama and also vowed to "smash" any attempt to destroy stability in Tibet.

The Dalai Lama and the government in exile call for greater autonomy for Tibet inside China, but Beijing views these demands as a separatist campaign liable to spark further demands for self-governance in other restive regions.

"We are ready at any time, any location to resume dialogue," Dicki Chhoyang, information secretary for the exiled government, told AFP.

Last week, UN High Commissioner for Human Rights Navi Pillay urged China to address Tibetans' grievances saying she recognised their "intense sense of frustration and despair which has led them to resort to such extreme means".

China rebuffed the criticism and expressed "strong dissatisfaction".