Local police chief Lieutenant-Colonel Salovdi Viskhanov and investigative chief Major Magomed Musiyev "were going home from work when their car came under fire," police sources told Interfax. Both officers died of their wounds, sources added.

In neighbouring Chechnya, a policeman who tried to defuse an explosive device found on the street, died when it exploded, sources told ITAR-TASS.

In Dagestan's Derbent region, a suspected guerrilla was killed in a clash with police after they stopped him to ask for his documents, Interfax reported.

The local pro-Kremlin authorities in Dagestan and other North Caucasus regions are battling to defeat an Islamist insurgency that has already killed scores of civilians and police.