Intense fighting has reportedly raged for a second night in the Georgian separatist region of South Ossetia.
Georgia's interior ministry reported air attacks on three military bases and key facilities for shipping oil to the West.
Interior Ministry spokesman Shota Utiashvili said the Vaziani military base on the outskirts of the Georgian capital was bombed by during the night and bombs fell in the area of the Baku-Tbilisi-Ceyhan oil pipeline.
He said two other Georgian military bases were hit and the Black Sea port city of Poti, which has a sizeable oil shipment facility, was bombed.
Utiashvili said there apparently were significant casualties and damage in the attacks.
Russia sent an armoured column into South Ossetia on Friday after Georgia, a staunch US ally, launched a surprise offensive to crush separatists. Witnesses said hundreds of civilians were killed.
The fighting devastated the capital of Tskhinvali, threatening to ignite a wider war between Georgia and Russia, and escalate tensions between Moscow and Washington.
Georgia said it was forced to launch the assault because of rebel attacks; the separatists alleged Georgia violated a ceasefire.
"I saw bodies lying on the streets, around ruined buildings, in cars," said Lyudmila Ostayeva, 50, who had fled with her family to Dzhava, a village near the border with Russia.
"It's impossible to count them now. There is hardly a single building left undamaged."
The fighting broke out as much of the world's attention was focused on the start of the Olympic Games and many leaders, including Russia's Prime Minister Vladimir Putin and US President George W Bush, were in Beijing.
The timing suggested Georgian President Mikhail Saakashvili may have been counting on surprise to fulfil his longtime pledge to wrest back control of South Ossetia - a key to his hold on power. The rebels seek to unite with North Ossetia, which is part of Russia.
Saakashvili agreed the timing was not coincidental, but accused Russia of being the aggressor.
"Most decision makers have gone for the holidays," he told CNN. "Brilliant moment to attack a small country."
Diplomats issued a flurry of statements calling on both sides to halt the fighting and called for another emergency session of the United Nations security council, its second since early Friday morning seeking to prevent an all-out war.
US Secretary of State Condoleezza Rice urged Russia to halt aircraft and missile attacks and withdraw combat forces from Georgian territory. Rice said in a statement the United States wanted Russia to respect Georgian sovereignty and agree to international mediation.
The leader of South Ossetia's rebel government, Eduard Kokoity, said about 1,400 people were killed in the onslaught, the Interfax news agency reported.
Georgia, which borders the Black Sea between Turkey and Russia, was ruled by Moscow for most of the two centuries preceding the break-up of the Soviet Union. Georgia has angered Russia by seeking NATO membership - a bid Moscow regards as part of a Western effort to weaken its influence in the region.
Saakashvili long has pledged to restore Tbilisi's rule over South Ossetia and another breakaway province, Abkhazia. Both regions have run their own affairs without international recognition since splitting from Georgia in the early 1990s and have built up ties with Moscow.
Georgia has about 2,000 troops in Iraq, as the third largest contributor to coalition forces after the US and Britain. Saakashvili told CNN the troops would be called home in the face of the South Ossetia fighting.
Georgia's Foreign Ministry accused Russian aircraft of bombing two military air bases inside Georgia, inflicting some casualties and destroying several military aircraft. Rustavi 2 television said four people were killed and five wounded at the Marneuli air base.
Twelve Russian troops were killed and 30 wounded in the fighting, said Russian Ground Forces spokesman Colonel Igor Konashenkov. Saakashvili said late Friday that about 30 Georgians had been killed "mainly members of the Georgian armed forces".
Putin warned in the early stages of the conflict that the Georgian attack would draw retaliation and the Defence Ministry pledged to protect South Ossetians, most of whom have Russian citizenship.
Chairing a session of his security council in the Kremlin, Russian President Dmitry Medvedev also vowed that Moscow will protect Russian citizens.
On Friday, an AP reporter saw tanks and other heavy weapons concentrating on the Russian side of the border with South Ossetia - supporting the reports of an incursion. Some villagers were fleeing into Russia.