KHYBER: A three-year-old boy was killed and five children were injured when a mortar shell struck a house in Manzaeo area of Tirah Valley on Wednesday. Mustafa, 3, was killed on the spot, and five children, identified as Naveed, Ajal Habib, Hazrat Ali, Zainullah and Noor Saeed, were injured. Local sources said the injured were shifted to a nearby health facility for treatment. In Bara, a policeman, Nadeem, received critical injuries in an armed attack by unknown assailants in Shalobar area on Wednesday. The police said the injured cop was shifted to Hayatabad Medical Complex in Peshawar in critical condition. Reason behind the attack could not be immediately known. The police registered a case against unknown assailants.