More Than 600 Are Reported Killed in Russian Offensive in Chechnya : Caucasus: Nearly half of the dead are said to be civilians. It is the worst fighting in the republic since federal troops took Grozny in January.

A ferocious government offensive to drive separatist rebels from the second-largest city in Chechnya has killed more than 600 people--nearly half of them civilians--the commander of Russian federal forces in the region disclosed Monday.

The staggering death toll from an 11-day battle for control of Gudermes underscored the utter collapse of a July cease-fire and hinted at the future of fierce insurgency likely to confront a new puppet leadership chosen for Chechnya in a Kremlin-orchestrated election.

Independent Television quoted Gen. Anatoly Shkirko, commander of federal forces in Chechnya, as saying the fighting had killed 38 federal troops, more than 300 Chechen “militants” and 267 civilians. Hundreds more were reported wounded.

The figures from the worst fighting since government troops took the Chechen capital, Grozny, in January prompted Russian Prime Minister Viktor S. Chernomyrdin to vow there would be no re-escalation of the year-old conflict that has already cost 20,000 lives.

“We will not let the Chechen war go into a second round,” declared the government chief who was instrumental in negotiating the now-defunct truce after a deadly hostage incident in the Russian town of Budennovsk in June.

Chernomyrdin expressed “big hopes” that Doku Zavgayev, the new Chechen leader who was elected in a Dec. 17 vote, will now have the authority to restore order in the breakaway republic and rebuild it within the Russian federal framework.

But Chechen rebels loyal to fugitive President Dzhokar M. Dudayev seized Gudermes on Dec. 14 in what both sides acknowledge was an attempt to disrupt an election that many Chechens viewed as a plot to bestow legitimacy on Moscow’s handpicked leaders for Chechnya.

After Dudayev guerrillas seized the railroad station and surrounded dozens of federal forces, government reinforcements unleashed a punishing barrage from heavy artillery and combat aircraft that sent civilians in the city of 60,000 fleeing into frozen cellars for cover.

The latest clash between federal forces and Dudayev supporters appeared to destroy the last shreds of the July 30 agreement to disengage and seek a political settlement of the conflict.

“A state of emergency is no longer expedient,” Russian Interior Minister Anatoly S. Kulikov told Independent Television, referring to the occupation by federal forces that has been powerless to prevent a resurgence of fighting.

“The federal troops will now disarm and annihilate criminal formations,” Kulikov said of the Dudayev loyalists.

His words foreshadowed a further intensification of the conflict that has worsened in the wake of several assassinations and attempts against the lives of Moscow-installed officials.

Kulikov insisted that the Dudayev forces had been routed, but he conceded that the guerrillas still at large remain strong enough to wage attacks on the federal troops who control most of the shattered republic.

The Kremlin sent soldiers and armor into Chechnya on Dec. 11, 1994, to quell a secession attempt by Dudayev, a Soviet-era air force general elected president of the republic after the 1991 breakup of the Soviet Union.

The election of Zavgayev ostensibly deposed Dudayev, but few Chechens regard the change in leadership as legitimate.