Russian soldiers halted their two-day offensive on the battered Chechen city of Gudermes on Friday without taking its rebel-held railway station.
Fighting flared last week in the year-old war with rebels trying to disrupt Russian-ordered elections for a new Chechen leader and for deputies to the Russian parliament.
Despite the retreat on Friday, Lt. Gen. Stanislav Kavun told the Interfax news agency in Moscow that Russian troops would press ahead with their drive to oust rebels from Gudermes, Chechnya's second-largest city.
Street fighting in recent days has been particularly intense around the station. Russian troops have been trying to free as many as 100 of their men who have been sealed off at the station since rebels seized it last week, Interfax said.
Federal troops halted their attack Friday after meeting heavy resistance as they moved closer to the station, the Russian command in Chechnya told Interfax.
Dozens of bodies reportedly were lying in the streets of Gudermes, located 20 miles east of Grozny, the Chechen capital.
Russian President Boris N. Yeltsin sent more than 40,000 troops into Chechnya a year ago in what was supposed to be a quick campaign to end the mostly Muslim region's three years of self-declared independence.
Meanwhile, the most notorious of Chechnya's rebel fighters on Friday threatened to contaminate a large area of Russia by blowing up a large container of radioactive material.
Shamil Basayev made the threat in an interview with independent NTV television at his base in Chechnya's snowy mountains.
Basayev made a similar threat last month and, to back it up, revealed the location of one such container. NTV unearthed the container in a Moscow park and found it contained radioactive cesium-137. Experts said that container did not contain enough of the isotope to pose a danger unless someone stood next to it for a long time.
But in the Friday interview, Basayev displayed what he claimed to be a 167-pound container of an unspecified radioactive substance.
Igor Sobolev, the director of an agency charged with cleaning up radioactive contamination, told NTV that Basayev's threat was a bluff.
"They blow it up and so what? Our experts come and clear it up in five hours," he said.