Three Georgian special forces personnel and 11 armed men, who allegedly crossed from Russia, have been killed in an exchange of gunfire in the deadliest violence near the border since their 2008 war, officials have said.
Georgia's interior ministry said the men died in clashes after it launched an operation to counteract an armed gang which had crossed the frontier from Russia's volatile North Caucasus region of Dagestan and taken hostages.
Nodar Kharshiladze, Georgia's deputy interior minister, said however that "we do not know who these people are" - a comment that avoided putting immediate blame for the incident on Tbilisi's rivals in the Kremlin.
"Three special forces personnel were killed and five wounded during the pursuit operation carried out by the interior ministry against the armed group which crossed into Georgia from Russia," Kharshiladze told the AFP news agency.
Two of the dead servicemen were interior ministry officers, while the third was a doctor serving with defence ministry special forces.
"Eleven members of the armed group were killed," Kharshiladze said. A further six gunmen were surrounded as the operation continued into Wednesday evening, he said.
"At this point we do not know who these people are and why they entered Georgian territory," he said, calling it the "worst incident" in terms of police casualties since the former Soviet state's five-day territorial war with Russia.
The ministry said that an unspecified number of hostages had been freed unharmed during the "anti-terrorist" operation which started overnight.
It released footage on its website showing two of the hostages that it said had been freed.
One of the reported hostages said they had been seized by a group of "armed, bearded men" on their way back to their village of Lapankuri after having a picnic in the Lopota Gorge near the border.
"They told us we were hostages and warned us they would shoot us dead if we tried to escape," the unnamed man said in the ministry's video.
"It was a group of about 15 heavily armed men, they had automatic rifles."
As the stand-off continued, Georgian television showed police vehicles moving armed officers in camouflage uniforms into the area and helicopters circling overhead.
Russian forces pushed deep into Georgia during the 2008 conflict to repel Tbilisi's military attempt to regain control over the Moscow-backed breakaway province of South Ossetia.
Tensions have remained high since the war and the two nations do not have diplomatic relations.
Russia, which has been battling separatist fighters in the volatile North Caucasus region, including Dagestan and Chechnya, has repeatedly accused Georgia of offering a safe haven to armed groups.
The Western-backed government in Tbilisi has consistently rejected Moscow's allegations.
After defeating Georgia's army, Russia was strongly criticised by the West for recognising South Ossetia and another Georgian rebel region, Abkhazia, as independent states and stationing troops there permanently - a move that
Tbilisi describes as occupation.