"The Tibet independence forces have indeed been engaged in activities to sabotage the Olympic torch relay in Lhasa," Baima Chilin, a vice chairman of Tibet's government, said before the relay.

Tibet has been under a security clampdown since peaceful protests on March 10 to mark the anniversary of a 1959 uprising against China's rule of Tibet escalated into widespread violence across the city on March 14.

That unrest spilled over into other parts of China with Tibetan populations.

'Order and stability'

The region is still closed to foreign tourists and foreign journalists have been allowed to visit only as part of closely monitored government tours.

Slogans on billboards and village walls in Lhasa welcomed the Olympics and urged locals not to cause trouble for the relay.

"Protect social order and stability," read one sign. While another urged Tibetans to "Harmoniously greet the Olympic Games".

The Dalai Lama has denied that he is planning to disrupt either the torch relay or the Beijing Games in August.

"Since this is a proud moment for the people of China, the Dalai Lama has appealed to Tibetans not to protest," Tenzin Taklha, a senior aide to the Dalai Lama, said from Dharamsala, the home of Tibet's government in exile.

The relay began at Norbulingka, the Dalai Lama's former summer palace from where Tibet's traditional Buddhist leader fled into exile in 1959.

It will end at the hilltop Potala Palace, the traditional seat of Tibetan rulers.