Georgia has claimed that jets flown from Russia fired a missile on its territory, narrowly missing a village.
However the Russian military has denied that any of its aircraft were in the region.
Georgian officials said part of a Russian rocket had been found in a field outside the village of Tsitelubani, in the disputed South Ossetia region.
Georgia and pro-Russian rebels have long clashed over control of South Ossetia and Interior Minister Vano Merabishvili said the incident was an act of aggression.
Georgia was ruled from Moscow until the break-up of the Soviet Union in 1991. The impoverished republic has since struggled to assert its sovereignty in the face of two wars fought by Russian-backed separatists in both Abkhazia and South Ossetia.
Russia formally recognises Georgia's borders, but has angered Tbilisi by maintaining close political and military contact with the rebel forces in South Ossetia.
Russian-dominated peacekeeping forces control a tense ceasefire in the region.
