Sergey Shamba, the foreign minister of breakaway Abkhazia, said a "Buk" (Nato specification SA-11 'Gadfly' for the original or SA-17 'Grizzly' for an upgraded version) ground-to-air air defense system was used to down four Georgian drones.

The Abkhaz side has claimed earlier that its missile-equipped aircraft of the L-39 type downed the Georgian unmanned reconnaissance drone, Hermes 450, on April 20.

The statement by Shamba is the first official acknowledgement by Abkhazia that it possesses such an advanced anti-aircraft system.

The Georgian authorities claimed earlier that the "Buk" systems were transferred from Russia to Abkhazia last year, as part of measures to boost the unrecognized state's military capabilities.

Shamba said, as quoted by Russian online news wire Regnum, that the system was a leftover from "the times of the [1992-93] war [with Georgia]". Although several Georgian aircraft were downed during the conflict, most kills were thought to have been due to hand-held anti-aircraft devices. The combat use of the "Buk" system was never reported.

Russia’s 643rd anti-aircraft regiment, which was stationed in the Abkhaz town of Gudauta during the 1992-93 conflict, reportedly possessed three "Buk" systems. Russia claimed the weapons were withdrawn and its military base closed in Gudauta in 2001, but international monitoring, something Georgia has requested, has never been allowed.

Georgian military obsevers have suggested that one of the key tasks of the Georgian drones in Abkhazia is to confirm the deployment of "Buk" systems. According to some sources, the "Buk", which is designed to fight attack aircraft and cruise missiles, is ill-fitted for use against small targets, such as unmanned aerial vehicles.

Although Georgia denied that its two drones were downed on May 4, officials in Tbilisi noted that the Abkhaz officials’ statements that they possessed anti-aircraft defense systems in the conflict zone was a violation of agreement. In a statement issued on May 5 the Georgian Foreign Ministry called on the UN Observer Mission in Georgia “to urgently launch probing into the presence of anti-aircraft defense systems and their use in Abkhazia and to immediately acquaint the international community with the results of this probe”.