Three policemen escorting a polio team were injured in firing by unidentified suspects in Tirah Mir Dara, a remote area in Khyber district, reported 24NewsHD TV channel.
According to police, the polio staff remained safe in the attack.
The injured policemen were identified as Nekmat Shah, Saddam and Gul Muhammad.
After the incident, a heavy police force reached the spot and launched a search operation in the area.
Reporter: Jahanzeb Khan