Chinese soldiers swarmed Tibet's capital on Saturday and cracked down on protesters, while police in another part of the country clashed with Bhuddist monks.
The main Tibetan exile group says it has confirmed that 30 protesters in Tibet have been killed in the crackdown following the worst unrest in two decades.
The Tibetan government in exile -- which is based in Dharamsala, India -- said the death toll in Tibet could be as high as 100, but could not verify that number.
State-run media in China had earlier reported that 10 people have died -- some burned to death -- in the worst uprising in the region in 20 years. Parts of the country are now under a strict curfew.
The Buddhist monk-led protests in Tibet started Monday, and are being held to commemorate a 1959 uprising against the Chinese government. Beijing has said Tibet is historically a part of China, but critics say it was independent for hundreds of years before Chinese troops moved in during 1950.
This week's protests turned violent Friday, with shops and vehicles set on fire.
On Saturday, the streets of Lhasa were mostly empty except for the baton-wielding police patrolling. Witnesses say Chinese soldiers and armoured vehicles are now in the city.
China told government workers to stay in their offices Saturday and has ordered tourists out of Lhasa, Tibet's capital.
Steve Chao, CTV's Beijing bureau chief, told Â鶹ӰÊÓnet that all roads into Lhasa have been blockaded and that a door-to-door search for demonstrators has been undertaken by Chinese security forces.
But the protest continued Saturday as hundreds of monks marched out of the Labrang monastery and into the town of Xiahe, gathering other Tibetans as they marched.
The Associated Press cites locals as saying the crowd attacked government buildings, smashing the county police headquarters before police fired tear gas and dispersed the crowd.
Lhadon Tehong, the executive director of Students for a Free Tibet, told Â鶹ӰÊÓnet on Saturday that her sources in China say the protests are spreading.
"People are talking about hundreds of hundreds dead," she claimed in the telephone interview from India, noting that official statistics are impossible to obtain.
'There's just so much resentment by Tibetans against China," Tehong said. "(China) is marginalizing them in their own land."
Chao said this marginalization has led Tibetan protesters to reportedly target ethnic Chinese that they've encountered.
"This is due to the growing resentment against the heavy handedness of the Chinese government," Chao said. "This is just a spill over from all of the suppression that they have been dealing with."
Olympics
There were worries that the protests were being timed in advance of the Olympic Games in Beijing.
Sun Weide, spokesperson for the Beijing Olympic organizing committee, says the protests will not have an impact.
Jacques Rogge, the head of the International Olympic Committee, says a boycott would only hurt athletes and won't help to resolve the situation.
There are plans to carry the Olympic torch across Mount Everest and Tibet, and Sun says those plans are proceeding smoothly and on schedule.
China plans for the torch to be carried to the top of Mount Everest, and has closed its side of the world's tallest mountain to prevent activists from disrupting the relay.
The mountain is in the border region between Nepal and Tibet.
The United States and other governments have urged China to show restraint in dealing with the protesters. But a Tibetan official is stating they will do otherwise.
"We will deal harshly with these criminals in accordance with the law," said Champa Phuntsok, chairman of the Tibetan government.
"Beating, smashing, looting and burning -- we absolutely condemn this sort of behavior. This plot is doomed to failure," said Phuntsok, an ethnic Tibetan, speaking on the sidelines of the National People's Congress, China's annual legislative session.
Police are saying that protesters who turn themselves in before Tuesday will be offered leniency. Otherwise, they will be "severely punished", according to a notice on websites and confirmed by prosecutors.
Phuntsok, blamed the protest on the Dalai Lama's followers. The Dalai Lama, who has been in exile since 1959, urged Tibetans "not to resort to violence."
Chao said that on Chinese state-run television, China has tried to downplay the protests and blame them on the Dalai Lama and his followers.
China maintains rigid control of Tibet, making independent reports very difficult to obtain. Journalists are rarely granted access to the region except under government-controlled circumstances.
With files from The Associated Press