A car bomb went off Friday in the capital of South Ossetia, Tskhinvali, killing seven Russian peacekeepers. Georgia has denied any involvement in the bombing and accused Russia of using the incident to try to delay its pullout from the buffer zone near South Ossetia, RIA Novosti reported.

"A new escalation in the South Caucasus is causing concern," the Russian ministry's press department said.

The Russian ministry said Foreign Minister Sergei Lavrov has sent a letter to his French counterpart, Bernard Kouchner, outlining "Russia's concerns regarding the provocation and deteriorating situation in the security zone."

The letter said Russia intends to withdraw its peacekeepers from Georgia by Oct. 10.

"Nevertheless, we firmly intend to fulfill the obligations agreed between the Russian and French presidents on the withdrawal of Russian peacekeepers from Georgia on Oct. 10, 2008," the ministry said.

Under a European Union-brokered peace deal, Russia has pledged to pull all troops out of the undisputed parts of Georgia within one month, leaving peacekeepers in South Ossetia and Abkhazia.