KARACHI, Pakistan 

A polio vaccination campaign was halted in a northwestern district of Pakistan on Thursday after over 100 policemen went on a strike following militant attacks targeting polio vaccinators and their security, officials said.

The policemen, who are routinely deployed to provide security to the polio vaccinators, staged a sit in near the local police head office in the Bannu district that borders the restless North Waziristan tribal region after one of their colleagues was gunned down by militants during an attack on an anti-polio team on Thursday.

This was the second consecutive attack on polio vaccinators in the northwestern Khyber Pakhtunkhwa province, which includes Bannu, in the past two days.

A policeman and a vaccinator were killed in a similar militant attack in the Bajaur tribal district on Wednesday.

“Negotiations are ongoing with the policemen, and there will be a solution hopefully," district police chief Ziauddin Ahmad told Anadolu over the telephone.

Ahmad claimed the polio vaccination campaign continued despite the strike, a claim rebuffed by a senior police official and locals.

“Polio vaccinators halted the campaign as soon as policemen deployed for their security left to join the strike," the police official said wishing not to be named.

Anti-polio campaigns in Pakistan are marred by violence. Militants often target polio teams and police assigned to protect them.

Militants loyal to Tehreek-e-Taliban Pakistan have long been targeting polio vaccinators in the southwestern Balochistan and northwestern Khyber Pakhtunkhwa provinces.

Polio is a highly infectious disease caused by poliovirus mainly affecting children under the age of five. It invades the nervous system and can cause paralysis or even death.​​​​​​​​​​​​​​