Aug. 1 (Bloomberg) -- Russia accused Georgia of firing at South Ossetia and warned that its troops may fight back, as the countries prepare for the first anniversary of the war over the separatist region. Georgia denied the claims.

Georgia launched mortars and grenades at observation posts near Tskhinvali, South Ossetia’s capital, over the past four days, Russia’s Defense Ministry said on its Web site today.

“The August 2008 event developed along similar lines,” the ministry said. If civilians or troops are threatened, “the Russian Defense Ministry reserves the right to use all forces and means at its disposal.”

Russia sent tanks, troops and jets into the former Soviet republic last year after Georgian President Mikheil Saakashvili attempted to reassert control over the breakaway region by force. Russia later recognized the sovereignty of South Ossetia and another separatist republic, Abkhazia, in a move opposed by the U.S. and Europe.

“Russia has once again showed an open threat towards Georgia and is trying once again to aggravate the situation,” Georgia’s Foreign Ministry said on its Web site.

President Barack Obama called for Georgia’s territorial integrity to be respected during a visit Moscow in July. The Black Sea country, a conduit for Caspian Sea energy to European markets that circumvents Russia, has been a recipient of U.S. aid and military training.

Russian President Dmitry Medvedev flew to South Ossetia for an unannounced visit less than a week later.

To contact the reporters on this story: Torrey Clark in Moscow at tclark8@bloomberg.net; Helena Bedwell in Tbilisi at hbedwell@bloomberg.net.

Last Updated: August 1, 2009 12:25 EDT