A Lada car stuffed with explosives with a strength of 20 kilograms of TNT equivalent exploded in the Dagestani city of Kizilyurt late Sunday, killing two policemen and setting their own vehicle on fire, police in Dagestan said.

"As a result of the explosion, two policemen died of their injuries on the spot," regional police said in a statement, adding their vehicle completely burned down.

"A crater with a diameter of around 1.5 meters and depth of 15 centimetres appeared at the site of the explosion," the statement said, adding the blast knocked out windows in nearby buildings.