TBILISI, Georgia — A car exploded Friday, killing seven soldiers outside Russia's military headquarters in South Ossetia, and Russian authorities charged it was a terrorist bombing meant to wreck the tense cease-fire that ended their war with Georgia.
Georgia's Interior Ministry blamed Russia, accusing it of arranging the blast to provide a pretext for delaying next week's scheduled withdrawal of Russian troops from Georgian territory around South Ossetia and another Kremlin-backed separatist region, Abkhazia.
The explosion, which the Russian military said also wounded eight Russian soldiers, was the deadliest single incident reported in South Ossetia since Russia and Georgia fought a five-day war over the breakaway region in August.
Under the Western-backed truce, European Union monitors have begun replacing Russian troops in the buffer zone ringing South Ossetia and the withdrawal is supposed to be completed by Oct. 11.
The Kremlin declined to comment on whether the carnage might affect the pullout timetable under its truce with this former Soviet republic.
A spokeswoman for the Russian-allied South Ossetian government, Irina Gagloyeva, said the car blew up after it was found, with weapons inside, in an ethnic Georgian village and confiscated.
South Ossetia's separatist president, Eduard Kokoity, called the explosion "a targeted terrorist act" and blamed it on the Georgian State Security Ministry, Russia's ITAR-Tass news agency said.
Russia's Defense Ministry characterized the blast as a "carefully planned terrorist act designed to undermine" the cease-fire.
The Russian commander in South Ossetia, Col. Gen. Marat Kulakhmetov, said two cars were confiscated by his troops in an ethnic Georgian village after a search found guns and grenades. The cars were moved to the military headquarters in Tskhinvali, South Ossetia's capital, and one of them _ with Georgian license plates _ exploded during a further search, he said.
Kulakhmetov said the blast was caused by a bomb with a force equivalent to 44 pounds of TNT. Televised footage showed a cloud of black smoke rising into the air, and South Ossetia's government said the blast shattered windows of nearby buildings.
There was no explanation of why a potentially dangerous vehicle would be taken to the headquarters or how a powerful explosive device could have been missed in the initial search.
South Ossetia's acting interior minister, Mikhail Mindzayev, said officials believed Georgian security agents had booby-trapped the car with explosives designed to go off "at the necessary moment."
The Georgian Interior Ministry put the blame on Russia. It charged that Russian intelligence services set off the blast to provide grounds for keeping Russian troops on Georgian territory.
There has been widespread looting and arson in ethnic Georgian villages in and around South Ossetia since the war. Residents and refugees from the area have reported the theft or confiscation of their cars by South Ossetian militias and marauders.
Despite high tension since the war, Russian troops at checkpoints on roads leading into South Ossetia from Georgian-controlled territory often carry out only cursory searches of cars, glancing in trunks and waving drivers through.
Under cease-fire agreements brokered by French President Nicolas Sarkozy on behalf of the EU, Russian troops are supposed to withdraw from buffer zones around South Ossetia and Abkhazia within 10 days of the Oct. 1 arrival of the EU monitors.
But Russia plans to keep 3,800 soldiers in South Ossetia itself and the same number in Abkhazia _ a presence that U.S., NATO and EU say violates its obligation under the cease-fire to withdraw to pre-conflict positions.
The war followed weeks of Russia and Georgia repeatedly accusing each other of plotting to spark an armed conflict over the separatist regions. It began when Georgia launched an offensive targeting Tskhinvali and Russia sent tanks, troops and warplanes that swiftly repelled the attack and drove deep into the ex-Soviet republic.
Russia's recognition of South Ossetia and Abkhazia as independent states has badly damaged already severely strained relations between Moscow and the West.
German Chancellor Angela Merkel told Russian President Dmitry Medvedev on Thursday that the West considered Georgia's territorial integrity "nonnegotiable," but Russia has made clear it will not back down.
Associated Press writers Matt Siegel in Tbilisi and Steve Gutterman in Moscow contributed to this report.