MOSCOW, October 4 (RIA Novosti) - Georgian special forces are suspected of plotting the Friday blast in the South Ossetian capital that killed seven Russian peacekeepers, a spokesman for Russia's top investigation body said Saturday.

"The team of investigators conducting a preliminary probe has every reason to suspect that the Tskhinvali explosion was triggered by Georgian special forces to destabilize the situation in the independent republic," said Vladimir Markin, spokesman for the Investigation Committee of the Russian Prosecutor General's Office.

Markin said the bombing had been defined as a terrorist act and a criminal case had been opened under the relevant clause of the Russian Criminal Code.

The Russian investigators are working in South Ossetia under the terms of the cooperation agreement signed by the two sides last month.

The explosion occurred Friday outside the headquarters of the Russian peacekeeping forces in the breakaway Georgian republic. A car bomb went off in a vehicle that had been moved to the capital, Tskhinvali, from a village in the buffer zone outside South Ossetia controlled by Russian forces.

The seven dead included a senior member of the peacekeeping force, Col. Ivan Petrik, while four seriously injured peacekeepers have been moved to Vladikavkaz in the Russian republic of North Ossetia to receive the necessary medical treatment.

Russia recognized South Ossetia and another disputed Georgian region, Abkhazia, on August 26, two weeks after it had forced out Georgian troops that had tried to retake control of the rebel republic.