A special task force soldier and three suspected "terrorists" were killed on Wednesday during a counter-terrorist operation on the outskirts of the Georgian capital Tbilisi, officials said.
Suspected terrorists barricaded in an apartment building "killed one serviceman and wounded four others," Nino Giorgobiani, spokeswoman for Georgia's security service, said in a statement.
"One of them was detained and three killed" during a special operation that lasted for more than 20 hours and ended in the evening, she added.
Citing preliminary information, she said the assailants were not Georgian nationals but "members of a terrorist group."
According to Giorgobiani, Georgia's security service was working to identify the group, with the help of international counter-terrorism organisations.
An AFP reporter who was in the area heard multiple explosions and gunfire in Tbilisi's suburban Isani district as armed counter-terrorist units raided an apartment block.
Security services said earlier Wednesday that several suspected members of a terrorist group "refused to surrender, opened fire with automatic rifles and threw hand grenades at counter-terrorist units."
Rustavi-2 TV aired footage of a burning apartment in a multi-storey residential building, with dozens of camouflaged soldiers and an armoured vehicle deployed at the site.
Georgia has no recent history of major terror attacks.
Some 50 Georgians are believed to be fighting alongside Islamic State extremists in Syria and Iraq, officials have said, mostly ethnic Chechen Muslim minority residents of a valley in the country's northeast, which has developed a reputation as a jihadist hotbed.
Ahead of, and immediately after, the 2008 Russia-Georgia war Tbilisi accused Russian security services of staging terror attacks against civilians and police, including planting an explosive device outside the US embassy in the capital.