GORI , Georgia (Agencies) - Russia sent hundreds of tanks and troops into the separatist province of South Ossetia and bombed Georgian towns Saturday in a major escalation of the conflict that has left scores of civilians dead and wounded. Russian jets have carried out strikes on military targets in the central Georgian town of Gori, close to the breakaway region of South Ossetia. Georgian officials say 60 people were killed when bombs hit two blocks of flats in the town. The Georgian parliament has meanwhile approved a presidential decree declaring a state of war for 15 days. The head of Georgia's national security council on Saturday did not rule out appealing for outside military help as the conflict in South Ossetia escalates. "I do not rule out a possibility of Georgia appealing to the international community for a direct military assistance," Alexander Lomaia told reporters by telephone in Brussels, where the European Union and NATO are headquartered. "However, our troops are fighting Russian invaders in a brave and brave manner," he said, adding: "Obviously, the resources are not equal." Earlier, Russia said it had "liberated" South Ossetia's capital Tskhinvali, but Georgia said it remained in control. Russian President Dmitry Medvedev said his country was seeking "to force the Georgian side to peace". Russian commanders announced earlier that they were sending more troops into South Ossetia and confirmed two Russian jets had been shot down over Georgia, without saying where. In another development, separatists in Abkhazia, Georgia's other breakaway region, said they had launched air and artillery strikes on Georgian forces in the Kodori Gorge. The crisis began spiralling when Georgian forces launched a surprise attack on Thursday night to regain control of South Ossetia, which has had de facto independence since the end of a civil war in 1992. The move followed days of exchanges of heavy fire with the Russian-backed separatists. In response to the Georgian crackdown, Moscow sent armoured units across the border into South Ossetia. Russian Foreign Minister Sergei Lavrov said about 1,500 people had been killed so far, including 15 of his country's soldiers. Georgian President Mikhail Saakashvili denounced the claims of a high civilian death toll as an "egregious lie". Mr Saakashvili also said he had decided to declare a "state of war" because Georgia was "under a state of total military aggression by the Russian navy, air force, large-scale ground operations". Georgia is withdrawing its entire contingent of 2,000 troops from Iraq to help deal with the crisis. US President George W Bush said the Russian attacks outside South Ossetia marked a "dangerous escalation in the crisis" and said Georgia's territorial integrity had to be respected. Fighting raged around Tskhinvali overnight and into Saturday morning, although not at the same intensity as on Friday, Russian media reported. Later, the Russian Army's Ground Forces commander, Gen Vladimir Boldyrev, told Russian media that his troops had retaken the city from Georgian forces. "Tactical groups have fully liberated Tskhinvali from the Georgian military and have started pushing Georgian units beyond the zone of peacekeepers' responsibility," he said, after paratroopers were airlifted into the city. But the secretary of the Georgian National Security Council, Khakha Lomaia, insisted that the city remained "under the complete control of our troops". Tskhinvali, where inhabitants are said to be sheltering in basements without electricity or phone lines, is reported to be devastated. The International Red Cross (ICRC) said it had received reports that hospitals in the city were "overflowing" with casualties. Georgia said Russia had also launched air strikes on targets inside its territory, in what it described as "a full-scale military invasion". Later, Russian aircraft bombed mostly military targets in Gori, where Georgian troops have been massing at three bases to support their forces engaged in South Ossetia. The BBC's Richard Galpin in Gori heard loud explosions and saw large plumes of smoke rising into the sky; soldiers and civilians were seen running through the streets. One missile hit a military base, from which most of the soldiers appeared to have managed to escape beforehand, he says. Our correspondent says injured civilians were being pulled from the buildings, which were on fire. The Georgian foreign ministry in Tbilisi said the Black Sea port of Poti, the site of a major oil shipment facility, had also been "devastated" by a Russian air raid. Georgian TV reported that the Georgian-controlled section of the Kodori Gorge in Abkhazia was under fire, blaming the bombardment on Russian forces. The foreign minister in Abkhazia's self-declared government, Sergei Shamba, said Abkhaz forces had launched an attack aimed at driving Georgian forces out of the gorge. It was not clear whether planes used in the attack on the gorge belonged to Russia or to the Abkhaz separatists. President Medvedev said Russia's military aim in South Ossetia was to force the Georgians to stop fighting. The UK, the US and France, are pinpointing what they say is Russia's aggression as the key factor in the slide towards war, while Moscow insists Georgia is to blame.