High hopes plummeted into fearful confusion in key Georgian cities Thursday as Russian troops appeared ready to pull out, then returned. Georgia's government said Russian tanks and other vehicles advanced toward the country's second-largest city but later stopped dozens of miles away.

Russia's Foreign Minister Sergey Lavrov, meanwhile, said the world "can forget about" Georgia getting back its two separatist provinces. And U.S. President George W. Bush demanded that Russia respect the "territorial integrity" of Georgia and urged it to honor a European-brokered cease-fire plan to end fighting that has displaced some 100,000 people.

Mikhail Saakashvili, speaking to foreign reporters in an appeal for international intervention, said a Russian armored convoy was moving toward the city of Kutaisi. Kutaisi, the country's No. 2 city, is toward central Georgia — not near the separatist provinces if Abkhazia and South Ossetia where fighting has erupted in recent days.

Georgian Prime Minister Lado Gurgenidze said it was "a rather large column of Russian armor, over 100 pieces." He said it had departed from the city of Zugdidi.

"We have no idea what they're doing there, why the movement, where they're going," he said in a telephone briefing. "One explanation could be they are trying to rattle the civilian population."

• Click here to view photos of the conflict in Georgia.

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Later, a Georgian Foreign Ministry spokesman said the troops were in the western city of Senaki, some 35 miles from Kutaisi. The spokesman was not authorized to be named. A Georgian government statement said the convoy had stopped in a village near Senaki.

There was no immediate response from Russia to the claims. Both sides have announced conflicting versions of events since the fighting broke out Aug. 7, when Georgia sought to retake breakaway, Moscow-backed South Ossetia and Russia responded with a fierce retaliation.

In Washington, White House press secretary Dana Perino cautioned against putting too much stock in the Georgian announcement about Russian tanks moving deeper into Georgia.

Saakashvili continued to press for help. "I think the world should think very carefully about what is going on here," he said. "We need to stop everything that can be stopped now."

Russia may be digging in for a military occupation of its diminutive neighbor despite a cease-fire, or it may be figuring out how to meet the truce's pullback provision without getting shot by furious Georgians. Russian troops were searching selected cities, forests and fields Thursday for military equipment left behind by Georgian forces.

Thursday's developments highlighted the challenges to the EU-sponsored cease-fire agreement. The accord had envisioned Russian and Georgian forces returning to their original positions.

On the edge of the strategic city of Gori, Georgian soldiers pointed their weapons at Russian forces and explosions and small arms fire broke out in the distance. Georgia, meanwhile, claimed Russians had left the oil port city of Poti, but hours later some forces were still there.

Defense Secretary Robert Gates warned if Russia does not pull back from Georgia it could hurt Moscow-Washington relations "for years to come." Still, he said he does not see "any prospect" for the use of U.S. military force in Georgia.

U.S. Secretary of State Condoleezza Rice flew into France on Thursday to support the EU cease-fire crafted by French President Nicolas Sarkozy. She was heading Friday to Georgia to press the president to sign the peace deal.

Relief planes swooped into Tbilisi with tons of supplies for the estimated 100,000 people uprooted by the fighting. U.S. officials said their two planes carried cots, blankets, medicine and surgical supplies — but the Russians insinuated that Georgia's U.S. ally might have sent in military aid as well.

Russia's deputy chief of General Staff Col.-Gen. Anatoly Nogovitsyn said he wasn't sure that the U.S. planes carried only humanitarian cargo. "It causes our concern," he said.

U.S. officials rejected the claim.

U.N. Secretary-General Ban Ki-moon warned Thursday that humanitarian aid groups and U.N. monitors are unable to relieve suffering in large parts of Georgia due to the ongoing fighting and lawlessness.

Georgia's Interior Ministry accused Russia of using Iskander short-range missiles on the port of Poti and in the strategic central city of Gori. Ministry official Shota Utiashvili showed reporters images of what he said were shrapnel and remains of the missiles. There was no immediate response from Russian officials to the claim.

Russian troops and Georgian troops briefly patrolled the strategic central city of Gori on Thursday, before relations between the two sides broke down and the Georgians left. At least 20 explosions were heard later near Gori, along with small-arms fire. It was not clear whether it was renewed fighting or the disposal of ordnance from a nearby Georgian military base.

Gori, battered by Russian bombing even before Tuesday's cease-fire, lies on Georgia's main east-west road only 100 kilometers (60 miles) west of Tbilisi.

Earlier, at a checkpoint outside Gori, Georgian Interior Minister Vano Merabishvili said Georgian engineers and special forces were combing the area for Russian mines.

"We are cleaning roads because we have information that there are some mines," he told AP.

A Russian envoy later denied that any roads around Gori were mined.

AP television footage showed Russian troops both inside and outside Gori, with plumes of black smoke rising from behind a forest.

Nogovitsyn said Russian troops went into Gori to establish contact with its civilian administration and to take control over military depots abandoned by the Georgian forces. "The abandoned weapons needed protection," he said.

An AP Television News crew heard explosions Thursday at a military base in Senaki and were told by officials from both Russia and Georgia that the Russians were destroying ordnance. Dozens of Russian armored vehicles and troops later set up for the night under camouflage on the main road from Senaki north to Zugdidi.

Russian troops operated with confidence Thursday in and around Poti, the site of Georgia's key oil terminal. Georgia's coast guard said Russian troops burned four Georgian patrol boats in Poti on Wednesday, then returned Thursday to loot and destroy the coast guard's radar and other equipment.

Georgian port authorities told an AP television crew in Poti that Russian troops were at the Poti docks early Thursday and APTN saw a destroyed Georgian military boat about 20 meters (yards) long.

The same APTN crew followed Russian troops on the outskirts of Poti as they searched a field and a forest at an old Soviet military base for possible Georgian military equipment.

Nogovitsyn would not comment on the Russian presence in Poti, saying only that Russian forces were operating within their "area of responsibility."

Another APTN camera crew saw Russian soldiers and military vehicles parked Thursday inside the Georgian government's elegant gated residence in the western town of Zugdidi. Some of the Russian soldiers wore blue peacekeeping helmets, others wore green camouflage helmets, all were heavily armed. Other Russian troops patrolled the city.

"The Russian troops are here. They are occupying," Ygor Gegenava, an elderly Zugdidi resident told the APTN crew. "We don't want them here. What we need is friendship and good relations with the Russian people."

Georgia, bordering the Black Sea between Turkey and Russia, was ruled by Moscow for most of the two centuries preceding the 1991 breakup of the Soviet Union. Russia has distributed passports to most in South Ossetia and Abkhazia and stationed troops they call peacekeepers there since the early 1990s.

Georgia wants the Russians out, but Russian President Dmitry Medvedev has insisted they stay.

Medvedev met in the Kremlin on Thursday with the two separatist leaders — a clear sign that Moscow is considering absorbing South Ossetia and Abkhazia.

In Tbilisi, displaced Georgians set up tents at a makeshift refugee camp, hanging washing on lines and rolling out mattresses and bedding.

"We have no beds, six of us are sleeping on the floor. We don't have anything left," a Georgian woman named Manana told an APTN crew. She would not give her last name, fearing reprisals.

A similar refugee camp was set up in Alagir, in Russia's North Ossetia province, for South Ossetians who had fled.

In London, BP PLC said it resumed pumping natural gas Thursday through one Georgia pipeline, but two oil pipelines in Georgia remain closed.

The Russian General Prosecutor's office said it has formally opened a genocide probe into Georgian treatment of South Ossetians. For its part, Georgia filed a suit against Russia in the International Court of Justice, alleging murder, rape and mass explusions of Georgians in both separatist provinces.

More homes in deserted ethnic Georgian villages in South Ossetia were apparently set ablaze, sending clouds of smoke Wednesday over the foothills north of Tskhinvali, the provincial capital.

Ethnic Georgians who have stayed behind — like 70-year-old retired teacher Vinera Chebataryeva — seem increasingly unwelcome. Chebataryeva sobbed to see that shelling had ripped two gaping holes in her apartment in Tskhinvali and destroyed her piano.

Janna Kuzayeva, an ethnic Ossetian neighbor, was not sympathetic.

"We know for sure her brother spied for Georgians," said Kuzayeva. "We let her stay here, and now she's blaming everything on us."