A police officer escorting a team of polio health workers was shot dead by unidentified gunmen in Khyber Pakhtunkhwa's Karak district on Tuesday, authorities said.

The slain officer was providing security to a team of polio health workers, who remain unharmed.

Karak's District Police Officer (DPO) Irfanullah, while confirming the incident, said that a search operation had been launched in the area to catch the culprits. He added that the polio vaccination drive — which began across the country on Monday — had not been halted after the incident.

KP Inspector General of Police Sanaullah Abbasi also took notice of the incident and said that the official's killers will be caught soon. He further said that security was being provided to polio workers and added: "The martyrdom of police [official] is proof that security is being provided."

Abbasi said that there are "some people" who were against polio vaccination but added that they would be rooted out soon.

Polio health workers and law enforcement officials who are tasked with providing security have often been targetted by militants and miscreants.

Pakistan and neighboring Afghanistan are the only two remaining countries in the world where polio is endemic, after Nigeria was last year declared free of the wild polio virus.

A five-day polio vaccination campaign started yesterday, during which over 40 million children under the age of five will be vaccinated across the country.

A supplementary dose of Vitamin A drops will also be administered to the children aged six to 59 months.

According to data issued by the National Emergency Operations Centre (NEOC) for Polio, around 285,000 polio frontline workers will visit parents and caregivers at their doorsteps, adhering to strict Covid-19 precautionary measures and protocols while vaccinating children. These measures will include wearing a mask, using hand sanitisers and maintaining a safe distance during vaccination.