The improvised explosive device (IED) was planted outside a basic health unit in Badabher area on the outskirts of Peshawar where vaccination materials were being distributed to volunteers.
A policeman and a volunteer of a pro-government peace committee were killed by the powerful blast. Eleven civilians sustained injuries in the incident, the latest in a string of attacks on volunteers engaged in Pakistan's polio eradication programme.
"The explosion caused by an IED targeted policemen," said SSP (Operations) Najeebur Rehman. The van was carrying policemen who had been tasked to protect teams going out to vaccinate children in the area.
Rehman said the bomb went off just as the police van reached the health facility to provide security to polio teams. The polio vaccinators were unhurt as they were inside the health facility, officials said.
The injured were taken to Lady Reading Hospital.
In 2011, Pakistan had 198 polio cases, the highest in the world. The figure was brought down to 58 last year despite opposition to the anti-polio programme from the banned Tehrik-e-Taliban Pakistan.
