MOSCOW, May 13 (RIA Novosti) - Two police officers and a civilian were killed when a roadside bomb exploded early on Wednesday in Russia's North Caucasus Republic of Chechnya, a police source said.

"The explosion occurred on a road near the village of Belgatoi as a police officer in a Lada drove by," the source said. "He and his two passengers, one of them also a policeman, were killed as a result."

Specialists are working at the scene to establish the type of explosive used.

The Kremlin announced a formal end to its 10-year counter-terrorism operation in the troubled region on April 16.