"A car was blown up in the city center, killing one person," Marat Kulakhmetov said. He added that he was unable to comment further until an investigation into the blast had taken place.
Two bomb attacks hit South Ossetia in February and late March leaving two people dead and about 20 injured. South Ossetia and Russia have alleged that Georgia was behind the blasts.
Both South Ossetia and another Georgian breakaway republic, Abkhazia, were involved in bloody conflicts with Georgia after proclaiming independence following the split-up of the Soviet Union in 1991.
Georgia is seeking to regain control of the republics and accuses Moscow of encouraging separatism and interfering in its internal affairs.
Last Friday, the State Duma, Russia's lower house of parliament, proposed that the president and the government consider the issue of whether to recognize the independence of Georgia's breakaway republics of Abkhazia and South Ossetia.
