Two policemen, positioned on security detail for polio campaign teams, were shot dead when unidentified assailants opened fire in Lower Dir, police reported on Wednesday. 

Saeedur Rehman, DSP Lower Dir, is reported to have said that, "The policemen were on their way to a basic health unit when they were targeted." The incident took place in Maiden region of the city and no polio team member was hurt because they were stationed away from the firing, added Rehman. 

"According to initial reports, the suspects managed to escape from the scene," he said, and an operation has been launched to search for the relevant assailants involved in the attack.

It is the fourth day of a five-day polio campaign, ongoing in Khyber Pakhtunkhwa, to vaccinate children under the age of five to stop an outbreak of the virus across the region.