By Lindsay Beck and Chris Buckley
BEIJING (Reuters) - Chinese troops moved to tackle moreunrest in ethnic Tibetan enclaves on Monday, as a deadlineloomed for "troublemakers" who took part in protests againstChinese rule in Lhasa that some say killed up to 80 people.
Lhasa, capital of the remote, mountainous region, was undertight police watch, but reports and officials saiddemonstrations by ethnic Tibetans flared in at least twoChinese provinces at the weekend, piling pressure on theCommunist authorities.
"We are completely capable of protecting the security ofthe Tibet people. Right now the overall situation in Tibet isvery good," the mayor of Lhasa, Doje Cezhug, said from Beijing,in remarks posted on the Tibet government's Web site.
But protests hit ethnic Tibetan areas in the Chineseprovinces of Sichuan and Gansu on Sunday, reducing the chancesof an early end to the instability that is a major challenge toChina's leaders just months before it hosts the Olympic Games.
In the Sichuan region of Aba, two ethnic Tibetans saidhundreds of People's Liberation Army vehicles moved inovernight, after unrest in which police said a crowd ofTibetans hurled petrol bombs and set a police station and amarket on fire.
"They've been driving through all night. It's just tailingoff now," the man said, adding that word had spread of protestsin other parts of the region as well.
In Gansu's Machu town, a crowd of 300-400 carried picturesof Tibet's exiled spiritual leader, the Dalai Lama, and shoutedslogans as they marched on government buildings, breakingwindows and doors and setting fire to Chinese shops andbusinesses, the Free Tibet Campaign said.
The London-based group said 100 Tibetan students staged asit-in at Northwest Minority University in Gansu's capital,Lanzhou, a worry for a country with a history of studentunrest, notably the Tiananmen Square protests of 1989 thatended in a bloody military crackdown.
In Lhasa, the situation was quiet but tense, with a heavypolice presence ahead of a Monday midnight deadline thatTibet's government set for protesters to give themselves up tothe police.
Otherwise, they would be "sternly punished", the region'sjudicial authorities warned.
The government advised foreign tourists to leave andconfirmed it had stopped granting foreigners tourist permits.
"If the Tibetans in Lhasa take to the streets again inlarge numbers and really challenge the Chinese authorities, Ithink we'll see a very harsh crackdown," said KennethLieberthal, a political scientist at University of Michigan.
The Tibetan Centre for Human Rights and Democracy, anon-governmental group in the Dalai Lama's base of Dharamsala,said security forces has already begun house-by-house raids.
Western governments have called for restraint in China'sresponse to the violent protests, and Chinese official mediatried to defend the security measures used in quelling them.
"Throughout the incident, Lhasa police officers exercisedgreat restraint. They remained patient, professional and wereinstructed not to use force," Xinhua news agency said.
China's rulers brook no challenge to their rule, and theunrest comes at a time of growing threats to social stabilityfuelled by inflation and a yawning gap between rich and poor.
The Dalai Lama, who has lived in India since 1959, the yearof a failed uprising against Chinese rule in Tibet, called foran investigation into what he called cultural genocide.Communist troops entered Tibet in 1950, after taking power inBeijing.
A Nobel peace prize winner, the Dalai Lama is revered inthe Tibetan community but reviled as a traitor in China, whereauthorities stepped up the rhetoric against him.
Xinhua quoted Tibetan officials as saying the Dalai Lama'scharge was "downright nonsense" and trumpeted its developmentpolicies in the region.
Critics say those policies helped fuel the protesters'anger by favouring Han Chinese migration to the region,contributing to a huge wealth gap between Chinese and Tibetans.
(Editing by John Chalmers)