GROZNY, Russia -- In the second week of a major drive to seize the capital of rebel Chechnya, Russian forces on Saturday unleashed an exceptionally fierce assault on Grozny, dropping scores of bombs on the city from low-flying jets.

Federal forces claimed progress against the rebels but apparently were still far from capturing the center of Grozny. Rebel fighters in heavily fortified positions have inflicted steady losses on Russian forces.Maj. Gen. Vadim Timchenko claimed 89 rebels, including several field commanders, were killed in Grozny on Friday and Saturday, the Interfax news agency reported. Timchenko said eight Russian servicemen were killed in the same period.

Smoke from blazing buildings covered parts of the Chechen capital after the overnight barrage, in which waves of bombs were interspersed with hundreds of rounds of shells fired by tanks in the hills at the city's edge.

Civilians in Grozny who have lived through more than three months of air attacks on the city said the overnight barrage was the worst they'd endured.

"There's never been anything like it was last night. It was simply a nightmare," said a 65-year-old woman who gave her name only as Anonina.

"The planes were like snakes, streaming past, over and over," said Lyubov Grigoryeva, 62, a pensioner. "This is how we spent New Year's."

Up to 40,000 mostly elderly and infirm civilians are trapped in Grozny.

Residents have been huddled for weeks in basements, too afraid to go outside or risk the journey through the Russian bombardment to escape Grozny.

There was no sign that federal troops were making significant progress on the ground, but the military claimed Friday to have broken through the rebels' first line of defense and to have taken control of the Staropromyslovsky neighborhood, about 2 miles from Grozny's center.

The Pentagon said Friday that Russia fired three Scud missiles into Chechnya. The missiles were monitored as part of the U.S.-Russia joint surveillance of any activity that might be related to the year 2000 computer glitch, but U.S. Undersecretary of State Thomas Pickering said the launches were not Y2K-related.

There had been no previous reports of Russia using such heavy weaponry in Chechnya. There was no Russian comment on the report Saturday.

After months of bombing and shelling the capital, the Russians launched an operation on Dec. 25 to capture Grozny, the last major Chechen city under rebel control and the war's key political prize. But Russian forces have been held up by heavily mined roads and tough rebel resistance.

Grozny is the only major town in Chechnya still held by the rebels after a three-month Russian ground offensive backed by intense air and artillery strikes.

The surprise resignation of President Boris Yeltsin on Friday and the appointment of Putin as acting president left Russia's strategy in Chechnya unchanged. Putin has championed the war and vigorously defended Russia against Western criticism of the offensive.

Putin said Saturday that Russia was ready for talks "anytime," but only with Chechen representatives who meet Moscow's oft-repeated preconditions: condemning terrorism, turning over criminal leaders and warlords, and freeing Russians and others who have been kidnapped for ransom and are being held in Chechnya.