GORI, Georgia — Russia pressed its invasion of Georgia by land, sea and air for a third day Sunday, striking far beyond contested South Ossetia as the Kremlin brushed aside a cease-fire offer and disputed Georgia's claim to have pulled its forces out of the rebel enclave.
Russian jets bombed near Tbilisi, the Georgian capital, including civilian housing, military bases, factories and the international airport, according to Georgian officials. Russian warships deployed off the Black Sea coast sank a Georgian missile boat that approached them, state-run Russian news media said.
Russian troops and tanks, meanwhile, took control of Tskhinvali, the devastated capital of South Ossetia, according to Russian state-run media, and there were reports that an armored column tried to push out of the separatist enclave's boundary toward the city of Gori before being turned back by Georgian forces. The military campaign also expanded, with Russian troops entering Abkhazia, another separatist province.
Tensions between the United States and Russia sharpened as the Bush administration suggested that Russia's objective goes beyond securing South Ossetia to the ousting of President Mikhail Saakashvili, who has close ties to the United States and is seeking admission to NATO.
Russia denied the charge, repeating that it is obliged to stop "numerous war crimes" against civilians, many of whom carry Russian passports, end a "major humanitarian disaster," and restore the situation to where it was before a Georgian military incursion on Friday.
Georgian police erected a checkpoint on the main road outside Gori, and warned travelers that the situation around the city of 50,000, home to a major military base, was too dangerous. During the day, Russian warplanes strafed the city.
Scores of Georgian tanks and troop-carrying trucks roared down the road in the direction of the Russian advance in the pre-dawn dark Monday. Dozens of other trucks were parked on the roadside. Four truck-mounted missile launchers sat just outside Gori, where troops shouted for cars to turn off their lights.
Georgian troops moved last week to seize South Ossetia, a mountainous enclave bordering Russia, after clashes with separatist fighters. Moscow, saying Georgian forces killed Russian peacekeeping troops and civilians, responded by launching missile, artillery and air attacks and pouring hundreds of tanks, armored vehicles and troops across the border.
The tiny former Soviet republic, nestled between Turkey and Russia, is considered strategically important because it is located on key energy and trade routes to central Asia. Russia, which ruled Georgia for nearly two centuries before the Soviet Union's collapse in 1991, considers the region as its backyard and opposes Georgia's admission to NATO.
Separatists began agitating for the secession of South Ossetia in the Soviet Union's waning days, igniting clashes with Georgian security forces that continued after Georgia became independent in 1991. Russia deployed peacekeeping troops in 1992. Negotiations to resolve continuing disputes have made no progress.
Russian troops have also been protecting Abkhazia, another rebel enclave, and reinforcements were added over the weekend, the military said. Moscow-backed rebels loosed "massive artillery fire" on Sunday at Georgian units just inside the province, an Abkhaz defense official told Interfax, a Russian state news service. Saakashvili accused the Russians of moving 100 tanks into Abkhazia.
As Russia moved more troops and tanks across its border into South Ossetia on Sunday, Saakashvili announced a withdrawal of Georgia troops from the province.
Georgia, he said, was also proclaiming a cease-fire, was ready to have it forces return to their positions before the fighting erupted and would sign an agreement for a peaceful resolution of the dispute.
"We need to stop hostility. We don't need further military action. We need to stop it. We need to bring back peace. And a cease-fire is about both sides," Saakashvili said on CNN.
But Russian officials rejected Saakashvili's claim of a troop withdrawal, saying that Georgian forces were continuing to fight.
Russian Deputy Prime Minister Grigory Karasin, speaking to reporters in Moscow, said that Moscow would discuss "all further issues" once Georgia pulled all of its forces out of "the combat zone" and immediately signed "a binding agreement on the non-use of force."
The United States and the European Union stepped up diplomatic efforts to end the bloodshed, estimated by Russians to have claimed more than 2,000 lives.
Secretary of State Condoleezza Rice was in touch with senior Georgian, Russian and European officials. French Foreign Minister Bernard Kouchner, whose country is the current EU president, flew into Tbilisi on a peace mission only 30 minutes after the Russian air strike on the international airport.
At the same time, the Bush administration, which has equipped and trained the Georgian army, sharpened its response to what it called Russia's "disproportionate" response over South Ossetia.
U.S. C-17s began flying home the 2,000 Georgian troops serving in Iraq. And Deputy National Security Advisor Jim Jeffrey, with President Bush in Beijing for the Olympics, warned "that if the disproportionate and dangerous escalation on the Russian side continues . . . this will have a significant long-term impact on U.S.-Russian relations."
Speaking at a meeting of the U.N. Security Council, U.S. Ambassador Zalmay Khalilzad said Russian Foreign Minister Sergei Lavrov admitted in a phone call with Secretary of Rice that Moscow wants Saakashvili replaced.
"'Saakashvili must go,'" Khalizad quoted Lavrov as telling Rice.
Asked by Khalilizad if Russia sought "regime change," Russian Ambassador Vitali Churkin replied tartly, "Regime change is purely an American invention."
Khalilzad, whose native Afghanistan was invaded and occupied by the former Soviet Union in 1979, later told reporters: "The days of overthrowing leaders by military means in Europe, those days are gone."
U.S. military officials were alarmed by Sunday's developments, calling reports of Russia's movements in Gori and its possible attempts to overthrow Saakashvili's government "far beyond" its stated objectives, one senior military official told McClatchy.