Three people died and 26 were injured in an attack on a military unit in the republic of Dagestan in Russia's North Caucasus, a law enforcement source said Sunday.

A car rammed the gates of a military unit of the 136th motorized rifle brigade in the town of Buinaksk early on Sunday, and an explosion followed. Earlier the Dagestani Interior Ministry said 13 were injured.

"According to updated information, three people were killed and 26 injured," the source said.

"Many of the injured are in a serious condition," he said.

Police said the explosion was most likely a suicide car bombing.

An investigation is underway.

Sporadic terrorist attacks and militant clashes are common in Russia's largely Muslim North Caucasus republics, especially Dagestan, Chechnya and Ingushetia.

The Kremlin has pledged to wage "a ruthless fight" against militant groups but also acknowledged a need to tackle unemployment, organized crime, clan rivalry and corruption as causes of the ongoing violence in the region.

MOSCOW, September 5 (RIA Novosti)