Policeman protecting Pakistani polio team killed

The attack took place as dozens of polio workers — including several women — were going door to door to vaccinate children in Gullu Dheri village of Swabi district in Khyber Pakhtunkhwa province, said senior police officer Izhar Shah. None of the polio workers the police officer was protecting were hurt in the attack, he said.

"The polio workers were terrified and immediately went back to their homes after the attack," Shah told The Associated Press. "The anti-polio drive in that village has been suspended."

Some Islamic militants oppose the vaccination campaign, accuse health workers of acting as spies for the U.S. and claim the polio vaccine is intended to make Muslim children sterile. Pakistan is one of the few remaining places where polio is still rampant.

In a separate incident in the northwest, a man wounded a polio worker with an axe.

The attacks occurred on the second day of a three-day campaign against polio that was launched by the provincial government. No one claimed responsibility for the shooting in Gullu Dheri, but suspicion fell on militants.

Suspicion of vaccination campaigns heightened considerably after it became known that a Pakistani doctor helped in the U.S. hunt for Osama bin Laden.

The physician, Shakil Afridi, ran a hepatitis vaccination campaign on behalf of the CIA to collect blood samples from bin Laden's family at a compound in Abbottabad in Pakistan's northwest, where U.S. commandos killed the al-Qaida leader in May 2011.

The samples were intended to help the U.S. match the family's DNA to verify bin Laden's presence in the garrison city.

In the recently released film "Zero Dark Thirty" about the search for bin Laden, a short scene shows a man going to the compound where bin Laden was hiding as part of a vaccination campaign. But in the movie, it's portrayed as an anti-polio campaign instead of anti-hepatitis.