At least four policemen were martyred Tuesday and as many sustained critical injuries in a rocket attack on a police van in Kulachi tehsil of Dera Ismail Khan, reported 24NewsHD TV channel.
According to police, the police van caught fire after it was attacked by terrorists with a rocket.
Four policemen were martyred on the spot.
The injured were rushed to hospital where the condition of three of them was stated to be critical.
The police launched a search operation for the arrest of the terrorists in the area.