Pakistan authorities have suspended the anti-polio campaign "for an indefinite period" across the country amid increasing violent attacks on polio workers.
A nationwide anti-polio drive was launched in all districts of the country on April 22.
The South Asian country's National Emergency Operation Centre (EOC) for polio directed all provinces on Friday to halt the drive, in an effort to protect some 270,000 polio field staff from attacks, Pakistan's Dawn newspaper reported on Saturday.
On Thursday, gunmen opened fire on female health workers in the southwestern town of Chaman, killing one and wounding another.
In Separate attacks on Tuesday and Wednesday, assailants killed two policemen that were assigned to protect a polio vaccination team in the northwest.
"After the Peshawar incident, the uncertain and threatening situation for the frontline polio workers has emerged and we need to save the program from a further major damage," Dawn newspaper quoted a statement issued by the EOC, adding that the Global Polio Eradication Initiative (SPEI) partners have backed the move.
"Hence, no further vaccination or catch-up activity will be conducted in any area for this campaign," said the EOC.
The violence coincided with rumors of children suffering from adverse reactions to a polio vaccine.