Russian officials said their jets had flown 100 combat missions in the past 24 hours, bombing rebel positions.

But Chechen officials said the air raids were indiscriminate, causing enormous civilian casualties.

Russian soldiers search a village 19 miles north of Grozny

Federal forces have clashed with Chechen gunmen in Tolstoi-Yurt, only 10km (six miles) north of Grozny.

A Chechen military spokesman said Russian planes also targeted the villages of Samashki and Bamut while federal troops had approached the outskirts of the stronghold of Gudermes.

There were no immediate reports of casualties.

The assaults over the past 24 hours were the heaviest since the 1994-1996 civil war that ravaged the republic but left Chechnya with de facto independence after Russia beat a humiliating retreat.

Grozny 'in ruins'

The international community has accused Moscow of using excessive force.

Russian Defence Minister Igor Sergeyev said that his forces would never return home without first conquering all of Chechnya.

"We have come with serious intentions. We plan to stay here forever," he said.

Chechen President Aslan Maskhadov, in a letter urging Pope John Paul II to use his influence to stop the Russian offensive, said 3,265 civilians had been killed and 5,000 others wounded since Moscow's first air assaults on 5 September.

"Innocent people, women, children and the elderly are dying to this day," he wrote.