Georgia's breakaway province of South Ossetia earlier accused Tbilisi of violating its airspace and firing missiles at its territory, after Georgia made similar allegations against Russia.
"According to our intelligence, an Su-25 aircraft that violated South Ossetian air space and dropped a missile over its territory, belongs to Georgia and is in service with the Georgian Air Force," Dmitry Medoyev said.
"We know that these [the Su-25] planes are flown not only by Georgian military pilots, but also by mercenaries, including from Ukraine," the official said.
Medoyev said the plane ditched two missiles on Tuesday. One of them fell near the village of Tsitelubani in Georgia and was discovered by peacekeepers in the conflict zone, and another missile fell near the South Ossetian village of Zakhor and has yet to be found, he said.
"South Ossetian police are searching for the missile, which could have simply fallen out due to sloppy fastening [on the aircraft's pilon]," Medoyev said.
South Ossetia, which declared its independence from Georgia following a bloody conflict that left hundreds dead in 1991-1992, is a sensitive issue in bilateral relations between Georgia and Russia.
Georgian authorities are seeking to bring it back under their control, and have accused Russia, which has peacekeepers in the area, along with Georgian and South Ossetian troops, of encouraging separatist elements.
On Tuesday, Georgian Minister for Conflict Resolution David Bakradze claimed that on the night of August 6 two Russian Su-25 Frogfoot aircraft illegally entered Georgian airspace and fired a missile at a radar station near the city of Gori. The missile did not explode and the radar was not damaged, he said.
The Russian Foreign Ministry immediately insisted on an investigation into the incident.
Vyacheslav Kovalenko, the Russian ambassador to Georgia, who was summoned Tuesday to the Georgian Foreign Ministry in connection with the dispute, told reporters after meeting with Georgian Foreign Minister Gela Bezhuashvili, that the Russian aircraft did not violate Georgia's airspace.
A Georgian official source clarified on Wednesday that the missile had been jettisoned, not fired, by a Russian aircraft fleeing Georgian airspace.
