Speaking to thousands of supporters, the Tibetan spiritual leader said Chinese martial law, and hard-line policies such as the Cultural Revolution, had devastated the Himalayan region.

"These thrust Tibetans into such depths of suffering and hardship that they literally experienced hell on earth," he said in this Indian hill town, where he and the self-proclaimed government-in-exile have been based since shortly after fleeing their homeland. "The immediate result of these campaigns was the deaths of hundreds of thousands of Tibetans."

Tibetan culture and identity are "nearing extinction," he told about 2,000 people, including Buddhist monks, Tibetan schoolchildren and a handful of foreign supporters. The group gathered in a courtyard that separates the Dalai Lama's home from the town's main temple, and monks blowing enormous conch shells and long brass horns heralded his arrival. "Even today, Tibetans in Tibet live in constant fear and the Chinese authorities remain constantly suspicious of them," the Dalai Lama said.

While his comments were unusually strong for a man known for his deeply pacifist beliefs, he also urged that any change come peacefully and reiterated his support for the "Middle Way," which calls for significant Tibetan autonomy under Chinese rule.

"I have no doubt that the justice of Tibetan cause will prevail if we continue to tread a path of truth and non-violence," he said.

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.