TBILISI, Georgia - Russia expanded its attacks on Georgia yesterday, moving tanks and troops through the separatist enclave of South Ossetia and advancing toward the city of Gori in central Georgia, in its first direct assault on a Georgian city with ground forces after three days of heavy fighting, Georgian officials said.
The maneuver - along with aerial bombing of the Georgian capital, Tbilisi - suggested that Russia's aims in the conflict had gone beyond securing the pro-Russian enclaves of South Ossetia and Abkhazia to weakening the armed forces of Georgia, a former Soviet republic and an ally of the United States whose Western leanings have long annoyed the Kremlin.
Russia's moves, which came after Georgia offered a cease-fire and pulled its troops out of South Ossetia, sparked widespread international alarm and anger and set the stage for an intense diplomatic confrontation with the United States.
Two senior Western officials said that it was unclear whether Russia intended a full invasion of Georgia but that its aims could go as far as destroying Georgia's armed forces or overthrowing its pro-Western president, Mikhail Saakashvili.
"They seem to have gone beyond the logical stopping point," one senior Western diplomat said.
The escalation of fighting between Russia and the former Soviet republic raised tensions between Russia and its former Cold War foes to their highest level in decades. President Bush has promoted Georgia as a bastion of democracy, helped strengthen its military and urged that NATO admit the country to membership. Georgia serves as a major conduit for oil flowing from Russia and Central Asia to the West.
But Russia, emboldened by windfall profits from oil exports, is demonstrating a resolve to reassert its dominance in a region it has always considered its "near abroad."
The military action, which has involved air, naval and missile attacks, marks the largest engagement by Russian forces outside its borders since the collapse of the Soviet Union.
Russia also escalated its assault yesterday despite strong diplomatic warnings from Bush and European leaders, underscoring the limits of Western influence over Russia at a time when the rest of Europe depends heavily on Russia for natural gas and the United States needs Moscow's cooperation if it has any hope of curtailing what it sees as a nuclear weapons threat from Iran.
Russian officials say Georgia provoked the assault by attacking South Ossetia last week, causing heavy civilian casualties. But Western diplomats and military officials said they worried that Russia's decision to extend the fighting and to open a second front in Abkhazia indicated that it had sought to use a relatively low-level conflict in a conflict-prone part of the Caucasus region to extend its influence over a much broader area.
There was heavy fighting on two fronts yesterday. Russian artillery shells slammed the city of Gori, a major military installation and transportation hub in Georgia. In the separatist region of Abkhazia, Russian paratroopers and their Abkhaz allies battled Georgian special forces and tried to cross the boundary into undisputed Georgian territory, Georgian officials said.
Russia bombarded Tbilisi's international airport shortly before Foreign Minister Bernard Kouchner of France, who was sent by the European Union to attempt a mediation, was due to land. It twice bombed a factory in the capital. Russia's Black Sea Fleet patrolled the coast of Abkhazia, and its Ministry of Defense said Russian warships had sunk a Georgian gunboat that fired on it.
The Kremlin declined to say whether its troops had entered Georgia proper but said all its actions were intended to strike at Georgian military forces that had fired on its peacekeeping troops in South Ossetia. Russia denied any intention of occupying Georgia.
"We have enough territory to think of," said a Kremlin spokesman, Aleksei Pavlov. "We don't need Georgia."
The Bush administration said yesterday that it would seek a resolution from the U.N. Security Council condemning Russian military actions in Georgia.
And in a heated exchange with his Russian counterpart at the United Nations, Ambassador Zalmay Khalilzad of the United States accused the Kremlin of seeking to oust Saakashvili.
"In that conversation, Foreign Minister Lavrov told U.S. Secretary of State Rice that the democratically elected president of Georgia 'must go,' " Khalilzad said. "I quote again: 'Saakashvili must go.' "
Khalilzad said the comment was "completely unacceptable."
In Washington, U.S. officials reacted with deepening alarm. They said Georgian troops had tried to disengage but that the Russians had not allowed them to.
"The Georgians told them, 'We're done. Let us withdraw,' " one U.S. military official said. "But the Russians are not letting them withdraw. They are pursuing them, and people are seeing this."
The official added: "The Russians have gained all of their military objectives. This is not about military objectives. This is about a political objective - removing a thorn in their side."
Tensions with Saakashvili escalated when he made a centerpiece of his presidency the reunification of Georgia with Abkhazia and South Ossetia, pro-Russian regions that won de facto autonomy in fighting in the early 1990s after the Soviet Union fell apart.
Russia has issued passports to many residents in the territories and has stationed peacekeeping troops in them. Heavy fighting broke out last week in South Ossetia when Georgian troops tried to take its capital in what now appears to have been a major miscalculation.
Russian officials say that up to 2,000 people have been killed in Tskinvali, the capital of South Ossetia, as Georgia pounded the city with Grad missiles, and that 30,000 have fled the territory into Russia. Refugees arriving in southern Russia reported mass devastation in the city.
Russia says it is acting to protect residents there and to punish Georgia for the assault, which Georgia says were to protect Georgian enclaves in the territory from attack and to push out what it said were illegally deployed Russian troops.