(CNN) -- A suicide bomb attack on a military unit in the Russian republic of Dagestan killed five people and injured 39, according to a law enforcement source cited by a Russian state news agency.
A car, filled with explosives and driven by a suicide bomber, detonated near the city of Buinaksk early Sunday, the news agency RIA-Novosti reported.
Dagestan is in the turbulent Caucasus region.
In recent years, the republic has faced ethnic friction, spillover from the discord in neighboring Chechnya and attacks on government officials by militant Islamists, the International Crisis Group has said.
On Saturday, a car bomb in Dagestan killed a driver and injured a government official and his two bodyguards, state-run news agencies reported.