PESHAWAR   -  Unknown gunmen shot and killed a police constable in Shaghalai area of Daudzai on Sunday. A police spokesperson said Asif Ullah, Constable Frontier Reserve Police, was on his way home after performing polio duty when unknown assailants opened fire on him. The policeman received serious bullet wounds and died on the spot. The killers managed to escape instantly. The police registered a case against unknown criminals and launched the investigation with no arrest made yet.