Violence broke in Lhasa, the Tibetan capital, on March 10 as protestors gathered to mark the anniversary of a 1959 Tibetan uprising.
Chinese authorities say that so far 13 "innocent civilians" have been killed, with an identical number of deaths among the security forces. Many people have also been injured, and shops and other buildings have been set on fire.
Tibetan leaders in exile have said that at least 80 people were killed during the March 10 protests. There have also been unconfirmed reports of more protests, and more deaths, in other areas of Tibet.
Chinese authorities have also set a midnight (16:00 GMT) deadline for protestors to hand themselves in to authorities or face "tougher" punishment.
Chinese officials denied on Monday reports that shots had been fired in Lhasa during the protests, with Qiangba Puncog, the Tibetan regional governor, saying that security forces had not carried guns or used "any lethal weapons," to put down the demonstrations.
He also said the Tibetan "mobs" had used methods that were "extremely ruthless." Chinese press reports said Tibetan protesters had been armed with steel rods, stones and Molotov cocktails.
The issue of Tibetan autonomy has long threatened to boil over into violent protests. Chinese troops first marched into the Himalayan kingdom in 1950, and the Tibetan spiritual leader, the Dalai Lama, was forced to flee to India in 1959, fearing arrest by Chinese authorities. He was accompanied by some 80,000 of his countrymen.
China has accused the Dalai Lama, who was awarded the Nobel Peace Prize in 1989 for his insistence on peaceful protest against Chinese rule, of being behind the latest protests. The Dalai Lama favors autonomy for Tibet, rather than outright independence.
Tibet has long enjoyed a high-profile in the West, with many celebrities and stars championing independence for the region, which is also popular among Western tourists. China has said that no foreigners were among the dead.
Beijing is set to stage the Olympic Games this summer, and the demonstrations in Tibet may well be part of a future wave of similar protests, both ethnically and politically motivated, timed to attract maximum publicity as the world media turns its attention on the country.
The Olympic torch is due to arrive in Tibet in a few weeks time in the build up to the Games.
Chinese authorities introduced on Saturday a temporary ban on foreign visits to Tibet, the Xinhua news agency said. Ju Jianhua, head of the Tibetan autonomy's foreign affairs office, called on foreigners currently staying in Tibet to leave the region in the next few days.
Beijing had earlier said that widespread international recognition of Kosovo's unilateral declaration of independence of February 17 could act as a precedent sparking conflicts within secessionist-minded regions within the world's most-populous country.
The Russian Foreign Ministry is advising Russians against traveling to Tibet, and has expressed the hope that China will take "necessary measures" to stabilize the situation.
"We express the hope that Chinese authorities will take all necessary measures to suppress unlawful actions and ensure the normalization of the situation in the autonomous region," the Foreign Ministry statement read.
