A top official of the military police has been assassinated in Russia's southern republic of Dagestan, in the restive North Caucasus region.

Officials say Shamil Murtuzaliyev, the deputy head of the special police division in Dagestan, was gunned down around noon local time Thursday in the region's capital, Makhachkala.

Russian news reports quoted a law enforcement official as saying police later killed three gunmen who opened fire after officers stopped their car. An investigation is under way.

Thursday's violence comes a day after an armed group killed a police officer and wounded seven of his colleagues in neighboring Chechnya.

Islamist separatists in Chechnya have fought two bloody wars against Moscow's rule since the mid 1990s. Some of the militancy has spread into neighboring Dagestan and Ingushetia.

Russian leaders have pledged to rid the restive North Caucasus of violence and improve its economy. High unemployment and low living standards are considered to be the main reasons driving local residents to join militant groups.

But despite major security sweeps in the mostly-Muslim region, attacks on government targets remain frequent.