After his speech, thousands of young Tibetans took to the streets of Dharmsala chanting "China Out!" and "Tibet belongs to Tibetans!"

While Beijing claims Tibet has been part of Chinese territory for centuries, Tibet was a deeply isolated theocracy until 1951, when Chinese troops invaded Lhasa, the regional capital. Tuesday's anniversary marked March 10, 1959 riots inside Tibet against Chinese rule which lead to a crackdown and, later that month, the Dalai Lama's dramatic flight across the Himalayas and into exile.

Last year, a peaceful commemoration of the 1959 uprising by monks in Lhasa erupted into anti-Chinese rioting four days later and spread to surrounding provinces - the most sustained and violent demonstrations by Tibetans in decades.

This year, China has largely sealed off Tibet to the outside world.

Recent visitors to Lhasa have described armed police posted on rooftops. Local governments in Tibetan areas have ordered foreign tourists out, and foreign journalists have been detained and told to leave. Internet and text-messaging services, which helped spread word of last year's protests, have been unplugged in parts of the region.

Following the protests, China has stepped up its campaign to vilify the Dalai Lama, accusing him of leading a campaign to split the region from the rest of the country.

The Dalai Lama insists, though, that he does not want Tibetan independence, saying he is only seeking greater autonomy for the region to protect its unique Buddhist culture.