China will not allow foreign observers into restive Tibet to probe human rights abuses and dismissed mounting international pressure for an independent investigation in the troubled mountainous region.

Some 68 Tibetans have set themselves on fire since March 2011 in protest against Chinese rule over Tibetan regions. At least 56 have died, according to Tibetan rights groups.

At least eight of the self-immolations had been reported in the Tibet Autonomous Region, a province-level administrative area under the central government. The rest occurred in Tibetan-populated areas of other provinces in southwestern China. The United Nations' most senior human rights official, Navi Pillay, urged China last week to allow independent human rights monitors to visit Tibet and address deep-rooted frustrations.

But a top Chinese-appointed official said this would not happen.

"We hope that [people] from all fields within the country and outside go to Tibet often to look around, study and travel, but as to some other aspects, we are not that welcoming," said Qiangba Puncog, chairman of Tibet's regional assembly.

"Those who think there are any problems in Tibet, human rights problems, arrogantly wanting to pursue investigations, to use these situations to propose entering Tibet, [I'm)] afraid we feel it's inappropriate," he said.

The remarks come as the Tibet government-in-exile said thousands of Tibetan students took to the streets in Rebkong county in eastern Qinghai province after a Tibetan youth burned himself to death on Thursday. Seven Tibetans have set fire to themselves in the past six days.