Two police officers were killed on Friday evening in an attack by unidentified assailants in Russia's North Caucasus republic of Ingushetia, a police spokesman said.

According to preliminary information, the gunmen opened fire on a police car in the town of Nazran at 18:20 Moscow time [15:20 GMT] and then fled the scene.

"Three policemen, who were in the car, sustained severe injuries. Two of them died on the way to hospital," the spokesman said.

The third policeman has been hospitalized and is in a critical condition.

Russia's North Caucasus region, which includes the volatile republics of Chechnya, Dagestan and Ingushetia, sees frequent attacks by militants on police, federal troops and officials.

ROSTOV-ON-DON, June 25 (RIA Novosti)