GROZNY -- Russian forces closed their grip Monday on the Chechen capital, Grozny, using helicopter gunships and heavy artillery to push to within 10 kilometers of the city in the first concerted ground assault since an ultimatum for Chechnya to disarm ran out Saturday night.


Russian troops captured the village of Petropavlovskoye, to the northwest of Grozny, and drove Chechen fighters back to the edge of the city, cutting off the main road west to the neighboring republic of North Ossetia for the first time in the conflict.


Chechen President Dzhokhar Dudayev issued an appeal for new talks, Reuters reported. But a brief statement did not make clear if he was ready to meet Russia's conditions for starting negotiations.


In Moscow, Prime Minister Viktor Chernomyrdin announced an intensification of the Russian military operation, while the commander of Chechnya's forces appealed for the entire Caucasus region to rise up in Grozny's support.


The afternoon saw truckloads of Chechen fighters being rushed up to the village of Dolinskoye, 25 kilometers northwest of Grozny, where small-arms fire crackled and tank rounds crashed between burning houses in the deserted village, according to reporters, who described the fighting as some of the worst since the conflict began.


Russian tanks could be seen lined up just above Dolinskoye, along a high ridge that runs north of the villages of Pervomaiskoye and Tolstoy-Yurt, just north of the city.


It was the first serious fighting since President Boris Yeltsin's extended ultimatum to the Chechen government to disarm expired Saturday midnight. On Sunday there were several bombing raids on targets around the capital, but no significant ground fighting.


On Saturday, Russian troops at a road block on the way out of Chechnya attacked a convoy of refugees, killing nine people, some as they ran from their cars, and crushed several of their vehicles under tanks.


The latest advance came as a meeting in Moscow chaired by Chernomyrdin announced a stepping up of "actions to eliminate and disarm illegal armed groups, while ensuring the safety of servicemen and Chechnya's peaceful population," Interfax reported.


Russian television said Yeltsin, who left the Kremlin hospital Monday, 10 days after minor surgery on his nose, appointed his nationalities minister, Nikolai Yegorov, as special representative in Chechnya.


In Chechnya itself, the commander of the republic's armed forces, Colonel Aslan Maskhadov, appeared on local television Monday urging the people of the Caucasus to "rise up and repel the aggressor." Numerous analysts have raised the fear that Chechnya's Moslem neighbors, in particular Dagestan and Ingushetia, could join a guerrilla campaign against Russian troops.


Grozny's television station was broadcasting normally Monday despite air raids directed at the television tower Sunday night. Citizens were kept awake all night as explosions boomed long into the early hours, rattling windows. Television transmission in the capital stopped briefly before resuming, although screens remained blank elsewhere in the republic.


The bombing appeared to be aimed at various strategic points, with bombs landing near the television tower, an electric generating station and a gas storage depot. No key installations were hit; the closest damage was four kilometers from the center.


Bombs destroyed a house near the television tower in the Oktyabrsky district, wounding a woman and killing several cows.


There were several sorties by military planes over villages south of the city Sunday afternoon and night. Tamara Magamadova, the head of the village administration of Gikala, 12 kilometers south of Grozny, said, "Four or five times they came over. We heard 20 or more bombs explode."


The village of 6,000 people escaped major damage; one Russian woman was taken to hospital, and windows were blown in.


It was the second night of bombing in Grozny after Yeltsin's deadline ran out midnight Saturday. Immediately at 12 midnight three planes roared over the sleeping city, bombing an unused cereal factory in the north of the city.


Dudayev's latest proposal for new talks came after both he and Yeltsin had said Sunday they still wanted peace negotiations. However, neither was prepared to accept the other's proposal for negotiations. Dudayev rejected a proposal to meet Russian representatives in the south Russian town of Mozdok, just outside Chechnya's borders, saying he would not discuss the republic's status with anyone but Chernomyrdin or Yeltsin himself.


But he said he would be willing to start peace talks in Grozny if Russia would send an emissary there -- a proposal rejected by the Russian side. A Kremlin aide said Moscow would not even respond to the offer.


Several countries have expressed concern about the intensification of the conflict, urging restraint and a peaceful settlement. In Ankara, the Turkish foreign ministry said Dudayev had appealed to Turkey to mediate, and a statement by Pakistan expressed sympathy and concern for the Chechen people on behalf of the Islamic world.


A statement from the European Union on Monday asked Yeltsin to use the minimum force necessary to resolve the conflict, while acknowledging the affair was an internal Russian matter.


But support for Yeltsin's tough stance was expressed Monday by Georgian President Eduard Shevardnadze, who is himself locked in a secessionist war with Abkhazia.