Three policemen were killed and two wounded after unknown assailants opened gun fire on their car in Buinaksk, a city in Russia’s North Caucasus republic of Dagestan, a spokesman for the local Investigation Committee said, according to RIA Novosti.

“At approximately 9:30 pm local time [on Tuesday, April 30] on the Shamil Street in Buinaksk unidentified assailants opened fire on a police car, killing three people and wounding two. The assailants escaped,” the spokesman said.

The search for the attackers is underway in the republic, he added.

The Islamist insurgency, once confined largely to the republic of Chechnya, has spread across the North Caucasus in recent years. Attacks on security forces, police and civilians are reported regularly in the neighboring republics of Dagestan, Ingushetia and Kabardino-Balkaria.