Leader of Georgia's breakaway region of South Ossetia, Eduard Kokoity, announced the closure of the administrative border with Georgia from Tuesday midnight, forbidding any vehicles or passengers to cross over.
A statement published on the website of South Ossetia's news department said the closure was aimed at "guarding against further provocations from the Georgian side."
However, Russia's RIA Novosti news agency said the closure was due to the threat of the A/H1N1 flu, as 12 Georgians were reported to have been infected.
Kokoity said on Tuesday that South Ossetia, supported by the Russian troops deployed in the border area, will adopt every measures to safeguard the security of the region.
Also on Tuesday night, the Russian troops kicked off military exercises in the border area.
Tensions in the border area between Georgia and South Ossetia were heightened days before the first anniversary of Georgia's brief war with Russia in August last year.
While Georgia accused South Ossetia of shooting at Georgian villages, South Ossetian authorities said the suburbs of its capital of Tskhinvali were attacked by Georgian mortars. No one was hurt in the shootings.
South Ossetia and Abkhazia broke away from Tbilisi's rule during a war in the 1990s that followed the collapse of the Soviet Union.
Russia and Georgia fought a five-day war last summer, when Georgia attacked South Ossetia to retake the renegade region that borders Russia. In response, Moscow sent in troops to drive Georgian forces out of the region.
Russia recognized South Ossetia and Abkhazia as independent states two weeks after the conflict ended.
Russian Foreign Minister Sergei Lavrov said on Tuesday that Russia did not plan the recognition of independence of the two regions until the last August's conflict began.
(Xinhua News Agency August 5, 2009)