Militants killed 12 members of the security escort for a polio vaccination team in northwest Pakistan on Saturday, detonating a roadside bomb before opening fire on their convoy, according to officials.
The attack lasted an hour and when rescuers approached the scene the gunmen also attacked them, according to Khan Faraz, an official in the Jamrud area of Khyber, a rugged tribal region bordering Afghanistan.
Around a dozen wounded were taken to hospital, but others died on the road waiting for help to arrive, he said.
Another official, Assistant Political Agent Jehangir Azam, said all the casualties were members of the levies or Khasadar, both locally recruited government-backed militias. They were providing security for the health workers.