Bombs rocked Tbilisi early Saturday morning as the fight between Georgia and Russia over a breakaway region intensified and moved into the Georgian capital.
Day one of the Georgia-South Ossetia military conflict
Government buildings, including the Parliament, were evacuated when the bombs fell.
Heavy casualties have reported on both sides since Russian forces moved Friday into South Ossetia, a pro-Russian autonomous region of Georgia.
Russian bombers were targeting Georgia's economic infrastructure, National Security Council secretary Alexander Lomaia said, including the country's largest Black Sea port, Poti, and the main road connecting the southern part of Georgia with the east and the airport.
Georgian television reported that the port had been destroyed.
Georgia, a former Soviet state, sent troops into South Ossetia on Thursday, aiming to crack down on the separatists, who want independence or unification with North Ossetia, which is in Russia. Russia responded Friday, sending troops into the Georgian province where it had peacekeepers stationed.
"I saw bodies lying on the streets, around ruined buildings, in cars," Lyudmila Ostayeva, a resident of the South Ossetia capital, Tskhinvali, told The Associated Press on Friday.
"It's impossible to count them now. There is hardly a single building left undamaged," she said after fleeing to a village near the Russian border, AP reported.
"They are killing civilians, women and children, with heavy artillery and rockets," Sarmat Laliyev, 28, told AP.
One U.S. State Department official called the conflict a "very dangerous situation" and said diplomatic moves are afoot around the globe to stop it.
Georgia -- on the Black Sea coast between Russia and Turkey -- appealed for diplomatic intervention. Watch Georgian minister describe fighting in South Ossetia »
Georgia asked the United States for planes to bring back its 2,000 troops serving as part of the U.S.-led coalition in Iraq, a U.S. official said.
"All day today, they've been bombing Georgia from numerous warplanes and specifically targeting [the] civilian population, and we have scores of wounded and dead among [the] civilian population all around the country," Georgia's president, Mikhail Saakashvili, said Friday. "This is the worst nightmare one can encounter." Watch the interview with Saakashvili »
Russia's ambassador to United Nations, Vitaly Churkin, put the blame on the Tblisi government.
"What is going on is a massive bombardment of residential quarters in Tshkinvali and other towns, too," Churkin said.
Eduard Kokoity, head of the rebel government in South Ossetia, said that 1,400 people were killed in the province, according to Russia's Interfax news agency.
Hundreds of people, possibly thousands, are fleeing South Ossetia to the Russian region of North Ossetia-Alania, the United Nations reported Friday, citing Russian officials.
About 150 Russian armored vehicles have entered South Ossetia, Saakashvili said, and Georgian forces had shot down two Russian aircraft. Watch the Russian tanks moving into the area »
Russian President Dmitry Medvedev, quoted by Interfax, said Russians had died because of Georgian military operations in South Ossetia.
Russia "will not allow the deaths of our compatriots to go unpunished," and "those guilty will receive due punishment," he said. "My duty as Russian president is to safeguard the lives and dignity of Russian citizens, wherever they are. This is what is behind the logic of the steps we are undertaking now."
South Ossetia, with a population of about 70,000, declared independence from Georgia in the early 1990s, but it was not internationally recognized. Many ethnic Ossetians feel close to Russia and have Russian passports and use its currency. iReport.com: Are you there? Share your photos, videos
Interfax quoted the Georgian Foreign Ministry as saying that strikes by Russian aircraft killed and wounded personnel at a Georgian air base and that Russian planes have been bombing Georgian territory throughout the day. Georgian officials also report four Russian aircraft shot down.
The U.S., NATO and the European Union have all called for an end to the fighting. President Bush and Russian Prime Minister Vladimir Putin discussed the conflict Friday, the White House confirmed.
By early evening Friday, a Georgian Cabinet minister said the country's forces have taken control of Tskhinvali, Interfax reported.
The Novosti news agency, citing the South Ossetian government, said Georgian tanks and infantry attacked Tskhinvali, and "a large part of the city has been destroyed. Over 15 civilians have been killed, several buildings are on fire in the city center, and the local parliament building has burned down."
But Russian and South Ossetian officials said Russia was making inroads in fighting Georgian forces.
"Street fighting in Tskhinvali has lasted for many hours. Ossetian home guards are using grenade-launchers to destroy Georgian tanks. Eyewitnesses say tanks are burning throughout the city. The turning point is approaching in the battle for the capital city," said the Web site of the South Ossetian Information and Press Committee.
The committee also said Russian armored vehicles have entered the northern suburb of the city.
Violence has been mounting in the region in recent days, with sporadic clashes between Georgian forces and South Ossetian separatists.
Georgian troops launched attacks in South Ossetia late Thursday after a top government official said a unilateral cease-fire offer was met with separatist artillery fire.
Lomaia said Georgian troops responded proportionately to separatist mortar and artillery attacks on two villages, attacks he said followed the cease-fire and Saakashvili's call for negotiations.
Russian peacekeepers are in South Ossetia under a 1992 agreement by Russian, Georgian and South Ossetian authorities to maintain what has been a fragile peace. The mixed peacekeeping force also includes Georgian and South Ossetian troops.