The incident occurred in a posh locality of Peshawar, the provincial capital of Khyber-Pakthunkhwa province.
Unidentified gunmen opened indiscriminate fire on the check post in which a head constable was killed instantly while another received serious injuries, police sources said.
Earlier in the morning, a Station House Officer (SHO) and two other police personnel were injured when some unidentified assailants opened fire on the SHO's vehicle in Peshawar.