Three suspected militants and a special forces soldier have been killed in a siege on an apartment in the Georgian capital Tbilisi, reports say.

Explosions and gunfire rocked a block of flats in the Isani district during the 20-hour stand-off, which officials say has ended.

One of the alleged militants was arrested and four soldiers were wounded, officials said. The suspects were not thought to be Georgian nationals.

Officials believed them to be members of a «terrorist group» and were working to identify which one, state security administration deputy chief Nino Giorgobiani said.

The security service said they had refused to surrender and were firing and lobbing grenades from inside.

Georgia, a mainly Christian country, has not had any jihadist-related incidents in recent years, correspondents say. But it is estimated that about 50 Georgians are fighting or have fought alongside the group known as Islamic State in Syria and Iraq.

They are mostly ethnic Chechens living in Georgia’s Pankisi Gorge, an area said to be a centre of Islamist extremism.