(ADDS details. Pictures) - by M.R. Narayan Swamy

NEW DELHI, Dec 1 (AFP) - Nearly 50 young Tibetans were arrested here Sunday when they tried to block Chinese President Jiang Zemin's convoy as he prepared to leave India after a path-breaking visit.

The protesting Tibetans, mainly in their teens, were beaten with bamboo canes and dragged by their feet by the police after they suddenly converged at a road junction, minutes before the arrival of the Chinese convoy.

Some Tibetan girls broke down as they were pushed into police vans, and shouted slogans hailing the Dalai Lama, the India-based Tibetan spiritual leader, and denouncing Chinese occupation of their homeland.

"Tibet is ours, Tibet is ours, Long Live the Dalai Lama," the emotionally-charged girls screamed. The protesting boys were also repeatedly hit with long canes by angry policemen desperate to remove them.

Barely seven minutes after the road was hurriedly cleared of the Tibetans, Jiang's convoy raced by the intersection towards an air force base from where the Chinese leader took off for Islamabad.

It was the fourth straight day of street protests by Tibetan exiles in the Indian capital against a three-day trip by Jiang, the first by a Chinese president to New Delhi.

Sunday's demonstration took the police by surprise. One officer said later there would have been a major diplomatic embarrassment if it had caused the convoy to halt or even slow down.

"We are sick and tired of these Tibetans," the officer said.

The authorities had deployed hundreds of armed police and paramilitary personnel along the circuitous route from the presidential palace, where the Chinese leader stayed, to the secluded air force base.

But the Tibetans, belonging to the militant Tibetan Youth Congress, reached the junction in a group and surprised the police by forming a chain. They then sat on the road and displayed anti-Chinese slogans.

A few held up huge posters of Jiang crossed out in red ink.

The demonstration led to an unprecedented traffic jam. The police pounced on the Tibetans and attacked them. Many Tibetans became emotional and wept when they were taken away.

India is home to more than 100,000 Tibetans, and the Dalai Lama's government-in-exile, which is not recognised by any country, is based in the northern Indian hill town of Dharamsala.

Tibetans routinely stage noisy and often dramatic protests whenever any Chinese leader visits India. On Saturday, nearly 100 Tibetans tried to storm the Chinese embassy but were arrested by the police.

A Tibetan protest rally was being planned for later Sunday.

Tibetan groups have denounced a ground-breaking agreement signed on Friday by India and China to slash troops on their winding disputed border, saying any pact involving Tibet should be approved by the Dalai Lama.

China and India fought a brief border war in 1962. The two sides also agreed to freeze cross-border military flights and to avoid the use of force against each other.