South Ossetia accused Georgian forces of firing mortars at the rebel territory today, and Russia warned Tbilisi it reserved the right to use force to defend civilians a year after their five-day war.
Georgia denied any shooting took place and, amid rising tension ahead of the August 7th anniversary of the war, said the Russian statement suggested "aggressive intent".
South Ossetia said two mortar rounds were fired at a military observation post from the village of Ditsi on the Georgian side of the de facto border, which runs a few hundred metres from the southern edge of the rebel capital Tskhinvali.
South Ossetia made a similar accusation on Thursday.
"In the event of further acts of provocation threatening the population of the republic and the Russian military contingent based in the territory of South Ossetia, the Russian Defence Ministry reserves the right to use all available force and means to defend the citizens of the republic of South Ossetia and Russian servicemen," the ministry said in a statement, Russia's Interfax news agency reported.
Russia crushed a Georgian assault on South Ossetia last August after months of escalating tension, sending tanks deep into Georgia proper and shaking Western confidence in oil and gas routes running through the volatile South Caucasus.
The West accused Russia of a "disproportionate" response during last year's war, and the European Union brokered a ceasefire and sent in monitors.
Russia recognised the rebel territories as independent states, backed by thousands of Russian troops, although the ceasefire called for a withdrawal to pre-war positions. The EU monitors are denied access to either rebel region.