The attack was the first serious incident since President Mikhail Saakashvili took over as the former Soviet republic's new president last Sunday.
A senior police official said an armed group, numbering six or seven men, carried out their raid on the village of Lia after crossing the internal border from Abkhazia region which has had de facto independence from the central government since the early 1990s.
"Four Georgian policemen and two attackers were killed," a local official said.
He added seven people were wounded.
The official said Russian peacekeepers, stationed on the border with Abkhazia, had helped to restore order.
Separatist conflict is one of the biggest problems facing Saakashvili.
Apart from Abkhazia on the Black Sea, the region of South Ossetia is also outside the control of the central government while another region, Adzhara, seeks greater autonomy from Tbilisi.
Besides leading a speedy economic recovery, Saakashvili has pledged to keep Georgia's territorial integrity.