Another policeman has been killed guarding a polio vaccination team in Pakistan.

He is the latest of the many victims who have been targeted in the last few months.

Health workers have received threats after the CIA used a vaccination campaign to hunt down Osama Bin Laden.

And the backlash is causing children to suffer.

Al Jazeera's Imtiaz Tyab reports from Karachi.

Source: Al Jazeera