Update to this story.

(RFE/RL) — A volunteer who was shot during a wave of attacks on polio-vaccination teams has succumbed to his injuries in Pakistan.

That brings to nine the number of health workers killed since December 17.

Officials say the student volunteer died on December 20, a day after he was shot while helping distribute polio drops in the northwestern city of Peshawar.

Five of the nine health workers killed were women.

The bloodshed prompted United Nations agencies to suspend their campaign against polio in Pakistan after the attacks.

The Islamic terrorist group Jundullah claimed responsibility, telling RFE/RL’s Radio Mashaal that polio vaccination is forbidden in Islam.