By Subir Bhaumik BBC eastern India correspondent

Police in Imphal, the capital of India's north-eastern state of Manipur, have fired in the air and used teargas to stop tens of thousands of demonstrators entering the central business district.

State officials said no one died, but the United Committee of Manipur, which called the protest, said more than 30 people had been injured.

The demonstrators were protesting at what they see as a move to transfer two hill districts to neighbouring Nagaland state, in an effort to end a 50-year-old rebellion there.

Tension started to rise in Manipur after leaders of the National Socialist Council of Nagaland arrived in Delhi last week to raise their demand for a greater Naga state.

The situation is now reported to be under control but very tense.

Anti-Delhi slogans

Tension rose after Naga leaders began peace talks

Police said thousands of demonstrators, most of them women carrying flaming torches, took part in Thursday's march.

They shouted slogans against the talks being held in Delhi between the NSCN and the government.

The NSCN wants to integrate Naga-inhabited areas of Manipur, Assam and Arunachal Pradesh states with Nagaland.

In June 2001, nearly 20 people died in Manipur in violence over the same issue.

Scores of official buildings, including the state assembly, were also burnt down.

Land worries

The United Committe of Manipur has asked all Manipuris working for the Indian Government to resign if any part of the state's territory is transferred to Nagaland.

It has also threatened to launch a secessionist campaign if this happens.

Nagas make up 60% of Manipur's hill regions.

Manipur's leading separatist group, the Manipur People's Liberation Front, has asked the NSCN to join hands and resume its separatist struggle.

NSCN leaders said recently their guerrillas would never again fight India.