Chechens Repel Assault on Stronghold : Caucasus: Russians, facing ‘overpowering fire,’ are beaten back from presidential palace. Confusion reigns in devastated capital. In Moscow, official vows fight will continue.

Chechen militants making a final stand Sunday inside the shell-riddled remains of Grozny’s presidential palace managed to beat back the Russian forces fighting doggedly to take full control of the rebel capital’s center, Russian officials said.

Hand-to-hand fighting for the palace, seat of the rebel Chechen government, was reported for the second day. In contrast to earlier reports, however, military sources told the Interfax news agency that Russian troops had not managed to penetrate the nine-story building.

The Russian attackers met “overpowering fire,” the agency said.

The prolonged failure to take the palace added to the overall humiliation the Russian military has suffered since it sent thousands of troops into Chechnya on Dec. 11 to break the Muslim region’s 3-year-old bid for independence.

Ill-prepared Russian soldiers sent on New Year’s Eve to take the city bogged down disastrously, and the continued push to take the capital is believed to have cost the Kremlin far more dearly than the latest official casualty count of 500 troops dead.

Still, the Russian government persisted Sunday, determined to wring victory from its Chechen offensive. Sergei V. Stepashin, the director of the Federal Counterintelligence Service, told Interfax that the principal Russian goal is still to take full control of the city center.

Stepashin, the Russian equivalent of the head of the FBI, said that federal troops control many of the blocks in Grozny and that pro-Moscow Chechens will soon begin setting up police stations there to maintain order.

But Grozny, a city of 400,000 that has now turned into such a grim wasteland that Russians compare it to the World War II battleground in Stalingrad, clearly remains a confusing patchwork of rebel- and Russian-controlled territory.

Russia’s NTV network reported that “it is practically impossible to say who is in control of certain districts of Grozny. The front line--if it exists at all--changes every minute, mostly due to the numerous salvos of Russian artillery.”

Russian officials claimed that Chechen rebels are running low both on ammunition and on people to continue the fight, but on Sunday there appeared to be a steady flow of militants out of the central city--to their homes on the outskirts, where they could rest--and back in.

The militants’ defiance does not seem to be flagging, and Chechen leaders have sworn that even if the presidential palace falls, they will launch an extended guerrilla war against the Russian troops.

“It seems that those who remain in the presidential palace are determined to die there,” a Russian officer who refused to give his name told Reuters correspondent Anatoly Verbin at the Mozdok air base, the Russian offensive’s command point.

Chechen President Dzhokar M. Dudayev maintained his bravado despite a special blow: His son Ovlur reportedly died last week of wounds received while defending Grozny. Few details were available as to how he died, but he had been reported wounded at the town of Argun more than a week ago.

In Moscow, more than 1,000 people gathered at central Pushkin Square on Sunday to protest the war and listen to Russian liberals such as Mikhail Molostvov, a Parliament deputy who recently returned from Grozny.

“Russian soldiers have become the hostages of the war,” Molostvov told the crowd. “Village boys were taken to Mozdok in trains, put into tanks without explanations and stupidly thrown in to attack the presidential palace. . . . All it takes is for a single Chechen to rise from the ruins of a house in front of the column and hit the first tank with his grenade launcher and the tank is on fire, and the kids die in the fire.”

In Washington, Secretary of State Warren Christopher said he will push the Kremlin to halt the fighting in Chechnya when he meets Tuesday with Russian Foreign Minister Andrei V. Kozyrev in Geneva.

“I’ll be urging him to stop the war as soon as possible; I will be urging him to seek reconciliation in Chechnya, to take into account the attitudes of the Chechen people,” Christopher said on the NBC-TV program “Meet the Press.”

He said that the Clinton Administration will continue to back Russian President Boris N. Yeltsin as long as he moves in the “right direction” toward democracy, but he also called the Chechnya crisis a major setback for Russian reforms.

Christopher may be in for a sharp conversation with Kozyrev, who has taken an increasingly nationalist line in support of the war.

As world censure of the offensive in Chechnya mounts, international aid has also begun to flow in.

A planeload of emergency supplies from the United Nations landed Sunday in the North Ossetian capital of Vladikavkaz, just outside Chechnya, carrying 42 tons of blankets, soap, plastic sheeting and medical supplies to help refugees. Tons more were expected to arrive Tuesday.