Two men were arrested yesterday for fatally shooting a gas-station attendant and then coldly looting the place of cigarettes as their victim lay dying, police said.

Christopher Roberts and Maurice Echols, both 21, were charged with murder and robbery for the July 25 slaying of Nadeem Khan, a 39-year-old Pakistani immigrant working the graveyard shift at a Mobil station in Flushing, Queens.

Roberts, who was taken into custody yesterday, told cops that Echols fired the fatal shot, a source said.

Echols was charged while in custody for another crime.