Indian police barred several hundred Tibetan exiles from marching to Tibet on Monday to protest Beijing hosting this summer's Olympic Games, as Tibetans marked their uprising against Chinese rule.

Protesters also held demonstrations in New Delhi and Katmandu, Nepal, where 10 activists were detained after hundreds clashed with police. Meanwhile, the Dalai Lama, the Tibetan Buddhist spiritual leader, speaking at a separate event, accused China of "unimaginable and gross violations of human rights" in the Himalayan region.

The planned six-month march from India to Tibet began Monday to coincide with the anniversary of a failed uprising against Chinese rule in Tibet that forced the Dalai Lama into exile in 1959.

• Click here for photos.

Local police chief Atul Fulzele said an order banning the marchers from leaving the area near the northern Indian city of Dharmsala, the seat of the Tibetan government in exile, had been issued following a recommendation from the Indian government.

India, which has been sympathetic to the Tibetan exiles in the past, has clamped down on such protests in recent years, fearing they could embarrass Beijing and damage burgeoning ties between the Asian giants.

Fulzele said the march contravened an agreement between New Delhi and the Tibetan government in exile. However, none of the groups taking part in the protest were affiliated with the government, and neither the Dalai Lama nor Tibet's government in exile have issued an official statement on the march.

Tenzin Tsundue, one of the march leaders, said they had not decided whether to defy the ban.

The exile groups said the march was to be one of several protests around the world before the Aug. 8-24 Beijing Games.

Beijing maintains that Tibet is historically part of China, but many Tibetans argue the Himalayan region was virtually independent for centuries. The groups say China is attempting to stamp out Tibetan Buddhist culture and increase the government's presence in Tibet.

Speaking Monday, the Dalai Lama said that for nearly six decades Tibetans "have had to live in a state of constant fear, intimidation and suspicion under Chinese repression.

"In Tibet, repression continues to increase with numerous, unimaginable and gross violations of human rights, denial of religious freedom and the politicization of religious issues," he said.

In New Delhi, more than 1,000 protesters marched, some wrapped in bandages covered with fake blood and wearing cutouts of the Olympic rings around their necks.

In Katmandu, police fired tear gas and beat up hundreds of Tibetans who threw bricks and stones at the police, officials said. At least 10 of the protesters were detained, said a police official who asked not to be named because he was not authorized to speak to the media.

Every year, some 3,000 Tibetans cross into Nepal, mainly through four passes across the Himalayas on their way to Dharmsala.