(Adds no Russian comment, background) TBILISI, Aug 24 (Reuters) - Georgian forces fired at an airplane they believed was Russian after it violated the Caucasus republic's airspace on Wednesday, a senior interior ministry official said. "The day before yesterday at 22:24 in the mountains of upper Abkhazia we opened fire on a Russian plane, after which we heard an explosion," Shota Utiashvili told Reuters on Friday. "The forest is on fire there, but we cannot confirm that the plane was shot down." Utiashvili could not say what kind of airplane it was, but insisted it was Russian. Russian officials could not be immediately reached for comment. The upper Abkhazia is a small mountainous part of Georgia's breakaway province controlled by Tbilisi. Georgia said on Wednesday two Russian planes briefly violated its border around the same area. Two weeks ago it accused Russian jets of dropping a missile near capital Tbilisi. Moscow has repeatedly denied Georgian accusations. Russia's armed forces chief of staff Yuri Baluyevsky has described Georgian claims as "hallucinations". (Reporting by Niko Mchedlishvili, writing by Oleg Shchedrov; oleg.shchedrov@reuters.com, oleg.shchedrov.reuters.com@reuters.net; +7 495 775 1242))
