1992 Georgia blames Russian forces for assisting the Abkhaz separatists during the conflict of the breakaway region Abkhazia
2006 Many Georgians suspect Russian involvement again in the breakaway region of South Ossetia
2006 Russia accuses Georgia of supporting fighters in Chechnya
2006 Tbilisi accuses Russia of trying to destabilise its economy by blowing up two pipelines carrying gas and banning Georgian imports
Georgia has summoned the Russian ambassador to hand him an official note of protest.
Dmitry Peskov, a Kremlin spokesman, said: "We categorically deny any involvement in these events. These declarations are not based on any reality."
Vano Merabishvili, the Georgian minister of interior, said: "Our radars show that these jets flew from Russia and then flew back in the same direction that they had come from... I assess this fact as an act of aggression carried out by planes flown from the territory of another state."
Government officials said the ordnance was dropped at 8pm (1600 GMT) on Monday evening, and that bomb-disposal experts were at the scene shortly after.
They said it hit the village of Tsitelubani, about 65km west of the capital, Tbilisi.
Shota Utiashvili, an interior ministry spokesman, said: "Fortunately it didn't explode. If it had exploded, it would have been a disaster."
He said nobody was hurt.
The village is a few kilometres to the south of Georgia's breakaway South Ossetia region, a long-standing cause of friction between Russia and Tbilisi.
|A crater left by the unexploded missile|
Russia, a financial provider for Georgia's rebellious Abkhazia and South Ossetia regions, has accused Tbilisi of pursuing anti-Russian policies.
During the rule of Eduard Shevardnadze, the ousted president, Georgia had accused Russia in 2002 of sending fighter jets on sorties over its territory, but Moscow denied any involvement.
At that time, Tbilisi alleged that Russian jets had dropped ordnance on uninhabited areas of the remote Pankisi Gorge in north-east Georgia, near the border with Russia.
Relations between Russia and Georgia deteriorated again last year when Tbilisi deported four Russian army officers, accusing them of spying.
Moscow responded by withdrawing its ambassador from Tbilisi and cutting air, sea and postal links with Georgia. Russia also deported several thousand Georgians, saying they were illegal immigrants.