Some 600 Russian troops in the Botlikhsky area fought at least 2,000 rebels, according to officials, who said the armed groups were well-equipped with automatic weapons, grenade-launchers and military vehicles.

By nightfall fighting had died down due to darkness closing in and the opposing sides were in a stand-off, while residents of the three villages fled their homes, the Itar-Tass news agency said.

Security forces in the Russian republic of Dagestan neighbouring Chechnya decided Saturday evening on a major operation to crack down on the insurgents, the Dagestan interior minister announced, quoted by Interfax news agency.

There were no immediate reports of casualties in the fighting, one of the worst outbreaks of violence along Dagestan's troubled frontier with Chechnya since the end of the Chechen war in August 1996.Prime Minister Sergei Stepashin ordered military chiefs to restore order in the region but stressed Russia had no intention of becoming embroiled in a repetition of the disastrous 1994-96 Chechen campaign.

Chief of Staff General Anatoly Kvashnin and Interior Ministry forces Chief Vyacheslav Ovchinikov were due in the region Sunday with a brief from Stepashin to ``normalise the situation,'' officials said.

The premier a leading hawk during the Chechen conflict said Moscow had the means and the strength to tackle the insurgency but insisted: ``We are not going to repeat the mistakes of 1994-95.'' That was a reference to the first year of Russia's bid to crush the Moslem republic's independence drive, which ended in humiliating failure for Moscow.

Unconfirmed reports said the insurgents were being led by Russia's wartime nemesis, Shamyl Basayev, a Chechen warlord still wanted by Moscow for his role in a daring raid on Budennovsk, in southern Russia, in which 1,000 people were held hostage. Saturday'sfighting erupted around 5 pm when Russian helicopter gunships strafed rebel positions around the village of Ansalta and Rakhata, in the Botlikhsky area on Dagestan's border with Chechnya, an Interior Ministry official told Echo Moscow radio.

An hour later Russian troops and interior ministry troops opened fire on rebel forces, thought to number between 200 and 500 men, said Abdulmanap Musayev, spokesman for the Interior Ministry of the southern Russian republic.

Russian forces were also battling to repel a large group of fighters in the Tsumada area, further along the border, where 11 people died in clashes Monday that the authorities blamed on Muslim fundamentalists bent on imposing Islamic rule in the republic and unification with Chechnya. Russian media reported that Arabic-speakers, nationals of Central Asian states and Dagestanis were involved in Saturday's clashes and were probably the same group involved in Monday's clash.

In Moscow, Chechnya's official representative, Mayerbek Vachagayev, saidGrozny had ``no contact of any sort'' with the insurgents, dismissing the matter as an internal Russian affair. Khumid Dalayev, head of the Chechen border guard service, told AFP that his forces were facing off against 200 Russian paratroopers at a separate sector of the Chechen-Dagestan border. The deployment, made by helicopter, appeared designed to cut off a possible line of retreat by the insurgents.

Moscow has taken an increasingly robust stance on the rising number of incidents on its troubled southern flank, using helicopter gunships to launch preventive strikes against suspected guerrilla bases inside Chechnya. Dagestan and the entire northern Cacasus region have remained in turmoil despite the August 1996 ceasefire which ended the Chechen conflict with Russia.

Neighbouring republics have seen a wave of hostage-taking from crime gangs based in the secessionist republic, and chronic poverty has compounded the inherent political instability in republics like Dagestan, which has a fragile mix of morethan 30 separate ethnic groups.

-- Agence France Presse