Islamabad: Pakistani policemen deployed in Pakistan's northwest Khyber Pakhtunkhwa province were fired upon by unidentified persons on Tuesday, resulting in the death of one cop and three injured.

The police sources said that they were on routine duty in the Lower Chitral area of the province when the incident happened, reported Xinhua.

"The cops tried to stop a vehicle at the check post for checking when the people on board fled by opening fire on them, leaving one policeman killed and the three others injured," the sources added.

There were three people in the vehicle, out of which two have been identified during the investigation process and are being searched for while the third one remains unidentified, the sources said.

The injured policemen have been shifted to a nearby hospital and their condition is stable, said the sources.

The identities of the attackers and their terrorist outfits have not been revealed by the sources, nor did any group claim the attack yet.