Islamabad, Feb. 3 -- A policeman was killed in firing by unidentified militants in Pakistan's northwest Khyber Pakhtunkhwa province on Monday morning, official sources said.

The incident happened at about 9:20 a.m. local time (GMT 0420) in the Khyber district, where the policeman, who was on duty as part of a polio vaccination campaign, was targeted, the sources from the district told Xinhua.

The assailants fled the scene after seizing the cop's submachine gun, the sources added.

No group has claimed responsibility for the attack yet. However, the sources indicated that the area has seen increased activities by militant groups, including factions associated with the banned Tehreek-e-Taliban Pakistan.

Police cordoned off the area, an...