Chechnya: Round two? Battle for the Caucasus Cat-and-mouse conflict Islamic roots in Dagestan Russia's demoralised army

Russia began its fifth day of air raids on Monday against the Islamic militants who have been attacking its territory.

Forty two people were killed and more than 200 injured as fighter-bombers blasted oil installations around the Chechen capital Grozny, a Chechen official told Echo of Moscow radio station.

Russia also stepped up its blockade, moving 200 pieces of heavy armour and artillery to its western border where many thousands of Chechen refugees have fled.

BBC's Rob Parsons in Moscow: "Another brutal awakening for the people of Grozny"

Earlier, Mr Sergeyev said he had not ruled out a ground offensive.

He said the aim of a ground invasion would be to eliminate militants and their bases and create a deep safety zone around the rebellious republic.

Click here to see a map of the conflict area

A BBC correspondent in Moscow says the scenes in Grozny are similar to those of the Chechen war five years ago, when Russia ended up defeated and humiliated.

Earlier raids badly damaged telecommunications facilities making it difficult to confirm reports from the region.

Russia says it is destroying the bases of Islamic militants following rebel attacks in neighbouring Dagestan.

In Dagestan, Russian reports say there were clashes in the Buinaksky district between police and a group of militants apparently trying to cross back into Chechnya.

Refugee exodus

Ingushetia has closed its border with Chechnya to halt the flow of refugees from its neighbour, Russian radio reported on Sunday.

The BBC's William Horsley reports: "The public mood is behind the army"

The closure is threatening to cause a humanitarian disaster with thousands left stranded on the roads leading to Ingushetia.

The head of the Ingush migration service, Kovsam Ozdoyev, told the radio that the number of refugees had been rising daily.

On Saturday, the Chechen authorities said at least 10,000 people had fled their homes to escape the bombing raids.

The Chechen Government said seven people had been killed during the strikes on Saturday, which included bombing runs on an oil refinery.

Television transmitters, a radio tower and a telephone relay centre were also knocked out.

Dagestan conflict

Russia accuses Chechnya of harbouring rebels who are trying to set up an Islamic state in neighbouring Dagestan.

It also suspects Chechen-based guerrillas of carrying out the recent bomb attacks in Russian cities that have killed some 300 people.

Russia's Air Force commander General Anatoly Kornukov said the raids would continue "until the job of killing off the fighters, their bases and sites supporting them is completed".

He said more than 2,000 militants had been killed and some 250 rebel strongholds and training centres had been destroyed in Chechnya and Dagestan since early August.