Threatened by a polio crisis fueled by Taliban attacks on health workers and resistance by anti-vaccination parents, Pakistan authorities are adopting an "iron fist" approach to eradicate the crippling disease.
Pakistan recorded 306 cases of polio in 2014, according to the World Health Organization, accounting for nearly 80 percent of all cases worldwide. Over the first two months of 2015, at least 13 new cases have been recorded.
In what has been branded a badge of shame by national media, tens of thousands of children go unvaccinated every year due to attacks against health workers that are carried out by the Pakistani Taliban, related refusals by parents to vaccinate their children, and the logistical challenges of vaccinating large numbers of persons displaced by conflict.
Much of the resistance stems from the Pakistani Taliban's open battle against polio vaccination campaigns, which it says are a front for espionage in areas under its control and an outside effort to sterilize Muslims.
According to data by Pakistani authorities, some 96 percent of polio cases were recorded among the Pashtun-speaking populations of the restive northwest -- Khyber Pakhtunkhwa province and the Federally Administered Tribal Areas (FATA).
Just days into a new vaccination drive, police have arrested some 500 anti-vaccination fathers in Khyber Pakhtunkhwa's provincial capital, Peshawar, and charged them with endangering public safety.
"Not only they didn't allow their own children to get vaccinated but they were also calling on other parents not to have their children immunized," Firuz Khan, a Peshawar police spokesman, told RFE/RL's Radio Mashaal.
The new campaign is aimed at inoculating some 2.7 million children in northwestern Pakistan against polio and several other diseases.
Peshawar Additional Assistant Commissioner Altaf Hussain says a total of 1,000 arrest warrants were issued in Peshawar and its rural outskirts. They target parents who are on authorities' list of "chronic" refusal cases, he said.
Hussain said more than 10,000 refusals have been recorded in the Peshawar area alone.
According to official data, nearly 60,000 children nationwide were left out of the polio-immunization campaign in January due to parental refusals.
"We are trying to put an end to these refusals," Hussain said.
Peshawar Deputy Commissioner Riaz Khan Mehsud was quoted as saying authorities will deal "with iron fist" with anti-vaccination parents.
City authorities told RFE/RL's Radio Mashaal that some of the parents who have provided a written pledged to have their children vaccinated will be released in the coming days.
Nearly 70 health workers and security escorts involved in vaccination campaigns have been killed in militant attacks in Pakistan since 2012.
Polio is a highly infectious viral disease that can cause paralysis and death. It primarily affects young children. There is no cure for polio once it is contracted. However, the virus is preventable through immunization.
Aside from polio, the World Health Organization (WHO) has warned that children in Pakistan are vulnerable to a number of other diseases, such as diphtheria, pertussis, measles, and bacterial pneumonia. The WHO has estimated that almost 3 million children in Pakistan miss out on a full course of the most basic vaccines nationwide every year.