MOSCOW: Five policemen were killed and 10 wounded Wednesday in an explosion in Dagestan, the Russian republic in the restive North Caucasus region, Ria-Novosti news agency reported quoting a local police official. A booby-trapped car exploded near the traffic police headquarters in Makhachkala, the Dagestan capital, the official said.

"According to preliminary information it was a terrorist attack," he was quoted as saying.

Concerns have mounted over increased militant attacks throughout Russia's Caucasus region, where Islamist militants have been battling pro-Kremlin local authorities and Russian security forces in a sporadic insurgency.