Russian security forces and Islamic rebels amassed troops and weaponry Monday in a rugged Caucasus Mountains region where the militants have seized several villages.
Russian troops accused rebels of shooting at Russian helicopters, including one carrying the armed forces chief of staff. He was not hurt and the aircraft was only slightly damaged, said Timur Abdullayev, a spokesman for the government of the southern republic of Dagestan.
The standoff, one of the worst in the area since Russia's disastrous 1994-96 war in neighboring Chechnya, began when Chechen militants moved into Dagestan on Saturday and occupied several villages just across the border in a rocky area accessible only by rough gravel roads and with few phone lines.
Federal and local troops moved in. Russian helicopter gunships fired on the rebels Saturday and Sunday but did not dislodge them.
The gunmen appeared to be members of the Wahhabi Islamic movement who support independence for Russia's mostly Islamic republics in the Caucasus.
Chechnya has had de facto independence since the Russian troops withdrew three years ago, though Moscow still claims it is part of Russia. Moscow has placed security forces along Chechnya's borders to try to fence it off, but warlords and criminal gangs roam the area and often venture into neighboring regions.
The latest conflict was complicated by yet another Russian government shake-up in Moscow. President Boris Yeltsin fired Prime Minister Sergei Stepashin and his government on Monday, the day after Stepashin flew to Dagestan to try to defuse the crisis.
It was unclear how the changes would affect Russia's approach to the Caucasus. Russia's Security Council met Monday to discuss the conflict.
Yeltsin's choice for prime minister, Vladimir Putin, head of the main successor agency to the KGB, said the fighting contributed to Stepashin's ouster, and he threatened to introduce a "special regime" in the republics bordering Chechnya, Russian news reports said. He did not elaborate.
Stepashin warned Monday, "We really may lose Dagestan," according to the Interfax news agency. "The situation is very serious."
Nearly 4,000 civilians had abandoned the captured villages by Monday, according to Mayor Said Amirov of Dagestan's capital, Makhachkala. Dagestan's government sent trucks to evacuate others and was setting up refugee camps at resorts and summer camps.
Refugees who arrived in Makhachkala said the rebel gunmen didn't threaten them and asked for their help in introducing Islamic law.
Dagestan's government opposes the Wahhabis and has shown no sign of splitting from Moscow, largely because its weak economy is heavily dependent on federal funding.