The Dalai Lama speaks to media next to Samdhong Rinpoche, the prime minister of the government-in-exile, at the Tsuglakhang temple in Dharmsala, India, on Tuesday. (Ashwini Bhatia/Associated Press)

Chinese rule in Tibet has created a "hell on earth" and caused the deaths of hundreds of thousands of Tibetans, the Dalai Lama alleged Tuesday in a speech to mark the 50th anniversary of his exile.

Speaking to about 2,000 supporters in Dharmsala, India, the exiled spiritual leader said decades under Chinese martial law and hardline policies such as the Cultural Revolution have devastated the Himalayan region.

"These thrust Tibetans into such depths of suffering and hardship that they literally experienced hell on earth," the Dalai Lama said. "The immediate result of these campaigns was the deaths of hundreds of thousands of Tibetans."

China has launched a "brutal crackdown" in Tibet since protests in the Himalayan region last year, he said.

He added Tibetan culture and identity are "nearing extinction" and that the Tibetan people live in "constant fear" of Chinese authorities who treat them like criminals.

China's Foreign Ministry spokesman called the Dalai Lama's remarks "lies." The Chinese governor of Tibet, Champa Phuntsok, said the claims about Tibetan deaths were "merely fabrication and vilification."

In his comments, the Dalai Lama urged change, but said it must come peacefully.

"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.

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

Tense atmosphere in Lhasa

On Tuesday, the Tibetan capital of Lhasa — where the uprisings of 1959 and 2008 started — was calm but tense, as was the rest of the region. Residents and businesses reported seeing increased patrols of armed police throughout the city. Tibetans and travellers in western China said police stepped up checks of identity cards.

"There are more paramilitary police in the streets. They're at bus stations, road intersections, even small alleys," said a staffer at the West Tour Go tourism agency in the capital, who declined to give his name for fear of drawing reprisals from the government, which has sought to hide the clampdown.

This year, China has largely sealed off Tibet to the outside world, with local governments ordering foreigners out of the area and communications cut off, including internet and text-messaging.

Since the protests, China 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 has denied the allegations, saying he is only seeking greater autonomy for the region to protect its unique Buddhist culture.

Following Tuesday's speech, marches were held in support of Tibet in Dharmsala, New Delhi, Seoul and Canberra. A rally was also expected to be held in Toronto.

With files from the Associated Press