More than 100 Tibetan refugees who were detained in India while attempting to march to the Chinese border have been placed in custody for 14 days.
The marchers, protesting against China hosting the Olympics, were detained near Dharamsala town, headquarters of the Tibetan government-in-exile.
The walk began on Monday as part of a global pro-independence protest.
It coincided with the 49th anniversary of the Dalai Lama's escape from Tibet after a failed uprising against China.
India has in the past been sympathetic to the Tibetan cause but in recent years Delhi's relations with Beijing have improved and India has not allowed large-scale public protests for fear of embarrassing Beijing.
The marchers were arrested on Thursday at Dehra Bridge, 31 miles (50 km) from Dharamsala, from where the Dalai Lama heads the Tibetan government in exile.
A New York-based human rights group has called upon China, India and Nepal to release Tibetan protestors detained over the last few days.
Human Rights Watch also said they should be allowed to demonstrate peacefully.
The protestors detained in India on Thursday were produced before a magistrate after their arrest.
They had spent the night in a government-run guest house near Dharamsala because the local jail cannot accommodate them all.
Dharamsala is home to many Tibetans, including the Dalai Lama
"They refused to sign a bond saying that they will not participate in any further protest activities for the next six months," said a press release by Tibetan activists.
"We condemn this decision by the Indian authorities to treat these peaceful Tibetan marchers as criminals," said a leader of Tibetan activists, Chime Youngdrung.
The Dalai Lama, Tibet's spiritual leader, has called for greater pressure on China over its human rights record.
An official at the Dalai Lama's headquarters said the leader was monitoring the situation very closely.
"The demonstrations have been totally non-violent, so we are concerned," Tenzing Takhla told the BBC.
Meanwhile, Human Rights Watch has urged India, China and Nepal to release the detained Tibetan protestors.
"Instead of arresting peaceful protestors, why don't these governments meet with them and attempt to address their grievances?" Sophie Richardson, Asia advocacy director at Human Rights Watch, said in a press release.
"Peaceful demonstrations are protected under international and domestic laws and they should be permitted, not violently dispersed."
Chinese officials have meanwhile acknowledged that Buddhist monks took part in protests in the Tibetan city of Lhasa earlier this week.
Foreign ministry spokesman Qin Gang said the authorities had "stabilised" the situation.
Unconfirmed reports earlier this week said as many as 600 monks had taken part in rallies, and that police used tear gas to disperse them.
Rights groups said the demonstrations were the biggest display of opposition to Chinese rule in Tibet since 1989.
The marchers say that their aim is to expose what they say are serious human rights violations in Tibet.
They say Tibetan refugees have the "right to return to Tibet".
As the Olympics draw closer, Tibetans have begun a global campaign to protest against Chinese rule in Tibet.
On Monday, some 1,000 Tibetan exiles clashed with police in the Nepalese capital, Kathmandu, while trying to march to the Chinese embassy.