Two policemen, deployed on a security detail for polio teams, were martyred after unidentified assailants opened fire at them in Lower Dir, police confirmed on Wednesday.

Lower Dir Deputy Superintendent of Police (DSP) Saeedur Rehman said the incident took place in Maidan area of the city. "The policemen were on their way to a basic health unit when they were targeted," he added. No officials from the polio vaccination team were hurt as they were at a distance from the firing, Rehman said.

He said a search operation had begun to find those responsible for the deaths. "According to initial reports, the suspects managed to escape from the scene," he added.

Wednesday marks the third day of the five-day polio campaign currently underway in Khyber Pakhtunkhwa.

Around 22,925 teams have been constituted to vaccinate 6.75 million children below the age of five. The campaign is focused on reaching and vaccinating every child in order to stop the transmission of the virus as well as its outbreak in the region.

Polio cases surge to 104

The total number of polio cases in Pakistan have surged to 104 during the current year. Pakistan is among a handful of countries that are still battling the disease which has been widely eradicated.

In a recent report, the World Health Organisation (WHO) predicted Pakistan as a polio-endemic state in 2020 as well.

The WHO report states that increased instances of polio cases in Pakistan in 2019 as compared to 2017 and 2018 highlights the continued geographic spread of the virus.

"The gaps in strategic implementation of vaccination activities in Pakistan means that there is a high likelihood that the number of cases will continue to increase and that transmission will continue well into 2020," read the report.