MAKHACHKALA, May 17 (RIA Novosti) - Three police officers and one civilian have died in militant attacks in separate incidents in Russia's North Caucasus over the past 24 hours, local police said on Sunday.

One policeman and one civilian were shot dead on Saturday night in the capital of Daghestan after unidentified assailants opened fire with assault rifles from a car. Both the officers and the civilian died in hospital without regaining consciousness, police said.

In a separate incident, a policeman and a local resident were wounded early on Sunday during a shootout with militants in the Sunzha district in the Republic of Ingushetia. During the clash, two gunmen were killed, local police said.

Also, a policeman from Chechnya died of wounds received during a sweep operation in Ingushetia.

Militant attacks and clashes remain common in Russia's North Caucasus although the Kremlin campaign to fight separatists and terrorists in Chechnya has officially ended. Violence often spills over into nearby republics, in particular Ingushetia and Daghestan.