The Dalai Lama called on Sunday for an investigation into China's tough response to protests in Tibet, and whether it was deliberate "cultural genocide".

The comments from Tibet's spiritual leader came as police and troops locked down Lhasa, the capital of Tibet, two days after street protests against Chinese rule that the region's government-in-exile said had killed 80 people.

"Whether the Chinese government admits or not, there is a problem. The problem is the nation with ancient cultural heritage is actually facing serious dangers," he told a news conference at his base of Dharamsala in northern India.

"Whether intentionally or unintentionally, somewhere cultural genocide is taking place", he said, adding that he wanted an investigation into the clashes.

The Dalai Lama, saying he felt "helpless", added that the international community had the "moral responsibility" to remind China to be a good host for the Olympic Games. He added that China should host the Games.

"So now we really need miracle power," he told a conference often interspersed with laughter from the exiled Tibetan leader.

There was no immediate comment from China's foreign ministry to his statements.

Monks first took to the streets of Tibet last Monday to mark the 49th anniversary of an earlier uprising, and protests soon spread to adjoining regions inhabited by pockets of Tibetans.

China has said at least 10 "innocent civilians" died, mostly in fires lit by rioters in Lhasa on Friday.

The convulsion of Tibetan anger at the Chinese presence in the region was a sharp blow to Beijing's preparations for the Olympic Games in August, when China wants to showcase prosperity and unity.

China has declared a "people's war" of security and propaganda against support for the Dalai Lama, the spiritual leader of Tibetan Buddhists, underlining that it will not heed calls from around the globe for a lenient response to the riots.

India hosts the Dalai Lama in the India city of Dharamsala, seat of the self-proclaimed Tibetan government-in-exile and the scene of daily protests in the past week.

Indian police this week arrested Tibetan protesters trying to march to the Chinese border, but a new group of protesters have now said they were marching to the border, challenging again the Indian government.

New Delhi is treading a delicate balance with its giant neighbour with whom it is trying to expand diplomatic and trade ties after decades of rivalry that included a brief war in 1962.

In New Delhi on Sunday, dozens of Tibetan protesters sat in a street near parliament and shouted slogans against China.

In Dharamsala's main Buddhist temple on Sunday, about 1,500 people gathered, including many monks, to listen to speeches from Tibetan exile leaders.

Chinese flags were laid out on the main road to the temple, forcing cars and lorries to drive over them. They were quickly covered in muddy footprints and tyre tracks.

"We are showing solidarity for people inside Tibet. We are the last hope for the people inside," said Sonam Dorjee, a protester leading a hunger strike near the Dalai Lama's house. - Reuters