Unidentified persons kidnapped and killed a police constable in Pakistan's North West Frontier Province (NWFP) Sunday, police said. The cop was kidnapped from a check post in Kohat near the troubled Waziristan tribal area. Police said four armed men abducted the constable, Nihad Hussain, from Ghamkol Police check post. They threw his body in the adjoining mountains after killing him.