The United Nations refugee agency has been told by the authorities in Ingushetia that 70,000 Chechen refugees have returned to Russian-controlled northern areas of the republic.

An estimated 150,000 to 180,000 refugees from Chechnya are believed to remain in neighbouring Ingushetia.

A spokesman for the UN High Commission for Refugees (UNHCR), Kris Janowski, told the Reuters news agency that there was no evidence that the refugees had been forced to back go back to Chechnya.

Human rights groups and refugees have reported that the authorities in Ingushetia and in Russia have been pressurising refugees to return home.

"The Ingush authorities have told us 70,000 people have gone back to northern Chechnya, where there is no fighting," Mr Janowski said.

"The conditions in the camps in Ingushetia are extremely harsh. They are also harsh conditions if they go back to Chechnya, but at least they are closer to home.

"The people are between a rock and hard place and it is easier to find accommodation in northern Chechnya than in Ingushetia, where they are staying in railway carriages and tents," he added.

Fears for Grozny

The UNHCR also expressed concern about tens of thousands of civilians trapped for weeks by fighting between Russian forces and rebels in the besieged Chechen capital Grozny.

Many lacked food, water and electricity amid severe winter conditions.

There had been no significant movement out of Grozny through humanitarian corridors set up by the Russian authorities, only a "trickle of people sneaking out", the UNHCR spokesman said.

"The fighting makes major movement impossible."

Aid workers boosted

Chechnya itself remains a no-go zone for international aid agencies, including the UNHCR and the International Committee of the Red Cross (ICRC), due to poor security and fears of kidnapping.

In recent weeks, the UNHCR has greatly boosted the number of its staff in the North Caucasus, Mr Janowski said. It now has nearly 100 staff in the region.

On Thursday, the agency's 20th convoy carrying relief supplies arrived in Nazran, Ingushetia, from the agency's base in the Russian city of Stavropol near the Caspian Sea.

Western donor countries have contributed $8m to the UNHCR's relief programme for displaced Chechens, fully funding its three-month emergency appeal launched to cover operations to the end of February.