The fighting that had sharply escalated when Georgian forces tried to retake the capital of South Ossetia, a pro-Russian region that won de facto autonomy from Georgia in the early 1990s, appeared to be developing into the worst clashes between Russia and a foreign military since the invasion of Afghanistan in 1979.
Shortly before dawn on Sunday, Georgia's Interior Ministry said that Russian bombers had begun striking military facilities adjacent to the civilian airport at Tbilisi. The explosions could be heard in the city, said Shota Utiashvili, a ministry official.
He said that Russia had built up large forces in Abkhazia and South Ossetia — breakaway regions that have support from Moscow — including as many as 300 artillery pieces in South Ossetia alone. Russian forces, he said, were also poised just over the border at Larsi, a checkpoint, where they could open a third line of ground attack.
As Russia moved more forces into the region and continued aerial bombing, it appeared determined to occupy both South Ossetia and Abkhazia.
Georgia's president, Mikheil Saakashvili, said Russia's ambitions were even more extensive. He declared that Georgia was in a state of war, and said in an interview that Russia was planning to seize ports and an oil pipeline and to overthrow his government.
Prime Minister Vladimir V. Putin of Russia left the Olympics in China and arrived Saturday evening in Vladikavkaz, a city in southern Russia just over the border. State-controlled news broadcasts showed Mr. Putin meeting generals, suggesting that he was directly in charge of military operations, eclipsing the authority of President Dmitri A. Medvedev.
Mr. Putin said that dozens of people had been killed in South Ossetia and hundreds wounded, and tens of thousands were reported to be fleeing. Georgia's health minister said that more than 80 people had been killed, including 40 civilians who died in airstrikes in Gori, a city north of Tbilisi. Another Georgian official said at least 800 people, almost all of them civilians, had been injured. Each side's figures were impossible to confirm independently, as was an earlier claim released by South Ossetians and repeated by some Russian officials that 1,500 people had been killed in the territory.
The fighting, and the Kremlin's confidence in the face of Western outcry, had wide international implications, as both Russian and Georgian officials placed it squarely in the context of renewed cold war-style tensions and an East-West struggle for regional influence..
Western influence over Russia appeared minimal. The East and West were stuck in diplomatic impasse, even as reports of heavy civilian casualties indicated that the humanitarian toll was climbing. The United Nations Security Council was meeting Saturday to discuss the crisis, but with no resolution.
Georgian officials said their only way out of the conflict was for the United States to step in, but with American military intervention unlikely, they were hoping for the West to exert diplomatic pressure to stop the Russian attacks.
“Georgia is a sovereign nation, and its territorial integrity must be respected,” President Bush said at the Olympics in Beijing. “We have urged an immediate halt to the violence and a stand-down by all troops. We call for the end of the Russian bombings.”
Senior European Union officials were adamant on Saturday that both Russia and Georgia were to blame for the recent escalation of the conflict, and that finger-pointing was counterproductive. Cristina Gallack, a spokeswoman Javier Solana, the European Union's foreign policy chief, said that the Union's immediate objective was to reach a cease-fire, and European envoys were reported to be en route to the region.
Other Western officials monitored the movements with alarm. “The record is crystal clear,” said a Western official, who spoke on condition of anonymity. “Russia has launched a full-scale military operation, on air, land and sea. We have entered a totally new realm — politically, legally and diplomatically.”
Russia appeared to be opening a second front in Abkhazia, to the west of South Ossetia, and to be aiming to drive Georgian troops from the Kodori Gorge, a small mountainous area in Abkhazia that Georgia reclaimed by force in 2006. Georgian officials said 12 Russian jets were bombing the area, shortly after a Western official said United Nations peacekeepers had withdrawn from the area at the request of Abkhazia's de facto government.
Russia also notified Western governments that it was moving ships of its Black Sea fleet to Ochamchire, a port on the Abkhaz coast. Georgian officials said they expected Russian troops to land there.
Mr. Putin made clear that Russia now viewed Georgian claims over the breakaway regions to be invalid, and that Russia had no intention of withdrawing. “There is almost no way we can imagine a return to the status quo,” he said in remarks on Russian state television".