Unidentified assailants opened fire on a vehicle in Khyber Pakhtunkhwa region of Pakistan which left at least one polio programme official dead, media reports said.

At least two policemen, who were escorting a polio vaccination team, died when armed men opened fire on them in Pakistan's Quetta region on Tuesday.

Taliban security officials have arrested four people accused of killing four polio vaccinators and two Taliban affiliates in Kunduz province of Afghanistan.