TBILISI, March 14 (Reuters) - Georgian President Mikhail Saakashvili lashed out at Russia on Wednesday branding as "barbarians" those who made a helicopter attack on a disputed gorge under Tbilisi's control. Georgian officials say three Russian helicopters fired late on Sunday at the Kodori gorge in the breakaway republic of Abkhazia, long the focus of tensions between Moscow and Tbilisi. Russia's air force denied any attacks and said all its aircraft near the area were grounded over the weekend. But Saakashvili made a thinly veiled attack on Russia at a meeting with residents of the gorge. "These people showed their real wild face to the world. They are barbarians who have continued stealthily into the twenty-first century," Saakashvili said. "You won't be able to force Georgia to her knees," he said after visiting a local school which was damaged in the attack. A group of officials from the Georgian interior ministry and United Nations military observers are investigating the incident. Relations between Tbilisi and its former Soviet master have soured over Moscow's support for Georgia's two breakaway regions of Abkhazia and South Ossetia. Tbilisi lost control over the regions in wars in the 1990s. The Kodori gorge is the de facto border between Abkhazia and Georgia. The upper part of the gorge is home to a local pro-Georgian administration, while the lower part is controlled by Abkhazian separatists. Saakashvili says he wants to bring Abkhazia and South Ossetia back into Georgia. Russian officials say Moscow's peacekeepers in the region prevent a bloodbath in the region.