A car exploded outside the Russian military's headquarters in South Ossetia on Friday, killing seven people and wounding three, the government of the Moscow-backed separatist region said.

The chief of the Russian military in South Ossetia said the dead were all members of the Russian peacekeeping force based there, Russia's Interfax news agency reported.

Russia's Foreign Ministry condemned the "crime" and said it was aimed at undermining efforts to ensure peace and security in South Ossetia and Georgia. However, there was no immediate indication that Russia would abandon its commitment to withdraw peacekeepers from a swath of land surrounding South Ossetia next week.

South Ossetia's separatist President Eduard Kokoity called the blast "a targeted terrorist act" and claimed the Georgian security service was behind it, ITAR-Tass reported. But neither he nor other South Ossetian officials provided significant evidence, and Georgia denied involvement.

Tensions remain high in Georgia following the August war that erupted when Russia's military repelled a Georgian attack aimed to regain control over South Ossetia.

The South Ossetian government said on its Web site that the car exploded near a building used by leaders of the Russian peacekeeping force after the vehicle was found packed with explosives in an ethnic Georgian village and confiscated.

Kokoity said the vehicle had been "acquired on Georgian territory" and brought to the peacekeepers' headquarters in South Ossetia's capital, Tskhinvali, to be checked, ITAR-Tass reported. He said the dead included people who had driven the car there.

Mikhail Mindzayev, South Ossetia's acting interior minister, gave a similar account on Russia's NTV television.

However, the accounts raised questions about why the Russian military headquarters building would have been put at risk by bringing a suspicious vehicle there that could be loaded with explosives.

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.

In postings on its Web site, South Ossetia's government said six people were killed by the blast and later reported that one of the four wounded had died in the hospital.

Kokoity said they included soldiers and civilians, ITAR-Tass reported. But Interfax quoted the head of the Russian peacekeepers, Col. Gen. Murat Kulakhmetov, as saying that seven Russian peacekeepers were killed and seven wounded.

Russian peacekeepers could not immediately be reached for comment.

Georgia's Security Council chief, Alexander Lomaia, denied Georgian involvement and told The Associated Press that Russian "occupation forces" and South Ossetian separatists bear full responsibility for what happens in areas they control.

The explosion came as European Union monitors are replacing Russian troops -- officially peacekeepers -- in territory ringing South Ossetia.

Under cease-fire agreements, Russian forces are to be withdraw from the territory by the middle of next week, but Russia plans to keep 3,800 troops in the separatist region itself -- a presence U.S., NATO and the European Union say violates its cease-fire commitments.

The cease-fire agreements also rule out the use of force, so Russia could conceivably use the explosion as a pretext to slow its withdrawal, but there was no immediate sign it would do so.

Russia's war with pro-Western, U.S.-supported Georgia and its recognition of South Ossetia and Abkhazia, another breakaway region, as independent states have badly damaged already severely strained relations between Moscow and the West.