Tibet's Communist Party chief vowed a trouble-free Olympic torch relay through the region, even as security forces struggled to stamp out flaring violence in a nearby part of Tibetan China.

Chinese security forces have locked down Tibet and neighbouring provinces to quell anti-Chinese protests and riots that started in mid-March.

But as late as Thursday night, rioting hit an overwhelmingly Tibetan area of Sichuan province, leaving eight dead, according to the International Campaign for Tibet, a Washington, D.C.-based group backing self-determination for the region.

Police fired on a crowd of locals and Buddhist monks after monks at the Tongkor monastery in Ganzi (Garze) Prefecture were held by police searching for images of the Dalai Lama, the Campaign said on its Web site (www.savetibet.org).

The monastery is home to 350 monks, according to its Web site (www.donggusi.com). Phone calls to the monastery and local government bureaus were not answered.

An earlier report on the riot by China's official Xinhua news agency said an official had been injured but did not mention any deaths. Foreign reporters cannot travel there to test the claims.

But despite the tensions, the hardline Party secretary of Zhang Qingli vowed a "faultless" passage for the Olympic Games torch when it passes through the region in coming weeks.

"Officials and masses from all ethnic groups must raise ethnic solidarity and make the successful passage of the torch through Tibet a heavy and glorious responsibility," Zhang said in a speech carried in the Tibet Daily on Saturday.

He said Lhasa was returning to normal after the unrest began there in mid-March, and once again blamed the exiled Tibetan Buddhist leader, the Dalai Lama, for inciting more violence.

The Olympic torch arrived in Beijing last month amid tight security, and will pass through Tibet in June after completing an international tour. Chinese climbers will attempt to bring a separate torch to the peak of Mt Everest, on the Tibet-Nepal border, early in May.

Zhang warned officials to be vigilant against any disruptions of the torch and said the journey could be a display of the region's stability.

"Tibet from top to bottom must keep a clear head at all times, without the lead relaxation of our vigilance," he said.

"Create a healthy social atmosphere of harmony and stability for the Beijing Olympic Games torch relay in the Tibet Autonomous Region."

WARNING SHOTS

On Friday, China's state-run Xinhua news agency said that "an official was attacked and seriously wounded" in the riot in Sichuan, adding that "local officials exercised restraint" but did not give more details on the incident.

"Police were forced to fire warning shots and put down the violence, since local officials and people were in great danger," Xinhua said in its English-language report, which was also carried in the China Daily on Saturday.

Chinese language media did not carry news of the incident.

Ganzi and neighbouring Aba in Sichuan province have seen torrid confrontation between Tibetan protesters and police in past weeks. Anti-riot troops have poured into the area.

Buddhist monks' protests against Chinese rule in Lhasa gave way to deadly rioting on March 14.

China says 19 people died in the Lhasa violence but representatives of the Dalai Lama say some 140 people died in the unrest across Tibet and nearby areas.