Around 15,000 police will guard the torch later on Thursday as it takes a relay route, already shortened because of fears of demonstrations, through the city's former British colonial boulevards that have been lined with barriers and wire meshing.

The torch, which is en route to China for the Summer Games in Beijing, was carried off a plane before dawn by Suresh Kalmadi, the chief of the Indian Olympic Association.

It was then taken along a route lined with hundreds of police to spend the rest of the night in a luxury hotel.

Police detained about two dozen Tibetan protesters along the route and in front of the hotel. Many were dragged into police vans as they shouted anti-China slogans.

The torch has been beset by protests through Europe and the Americas, mostly over a Chinese crackdown in Tibet. In some places, protesters tried to snuff out the flame and organisers extinguished or hid the torch to keep it safe.

Fearing similar protests, India trimmed the route to a third of the original 9 km (5 mile) distance, restricting it to a high-security stretch used for the annual Republic Day parade in the Indian capital.

"The security is very, very tight and we are not talking about the minute details at all to ensure there is no disruption during the rally," Rajan Bhagat, a police spokesman, said.

India has been a centre of regular protests for weeks and exiles even tried to scale the walls of the Chinese embassy.

Tibetans plan to hold a parallel torch relay on Thursday to protest against Chinese action and demand Tibet's independence.

Wearing "Free Tibet" bandanas and t-shirts, many Tibetans had already gathered for their rally.

"No Beijing run in India," one of the banners read.

Newspapers warned of traffic gridlock on Thursday in the capital, so tight is the security. One large school near the Chinese embassy has warned parents of the dangers of tear gas from police wafting into classrooms if there are protests.

The Dalai Lama has voiced his support for the Beijing Games. He has urged Tibetans to desist from disrupting the torch relay.

But protests have continued unabated. India had to assure China of adequate security for the torch after the Chinese foreign minister called his Indian counterpart this month.

India has been reluctant to criticise China over Tibet, despite some public support for the exiles as well as criticism in the media of New Delhi's soft line.

Despite years of mistrust and a border war in 1962, a booming India is seeking closer relations with China, which is now one of its biggest trading partners.

A total of 70 torch-bearers, including 45 current and former athletes, will carry the torch.

But Indian football captain, Bhaichung Bhutia, has refused to carry the Olympic torch in protest against China's response to the unrest in Tibet.

One of India's most famous cricketers, Sachin Tendulkar, has pulled out of the relay for personal reasons.

The torch was in neighbouring Pakistan on Wednesday.