Unidentified armed men gunned down a police constable here on Wednesday and escaped the scene. The incident took place in Distri No 6 of tehsil Kalachi in Dera Ismail Khan where gunman shot dead police constable Imran and fled after committing the murder. The deceased cop was serving as gunman of Sitara Afreen, the mother in-law of PTI MNA and Parliamentary Secretary Sheikh Yaqoob. The body was shifted to hospital for postmortem and the police after registering a case against unidentified murderers have started an investigation.