A powerful roadside bomb exploded near a vehicle carrying police officers assigned to protect polio workers in restive northwest Pakistan on Tuesday, killing three officers and wounding two others, police said.
The attack occurred in Dera Ismail Khan district, Khyber Pakhtunkhwa province, as officers were returning to their stations, local police officer Nasir Khan said.
No one has so far claimed responsibility for the attack, which came a day after unidentified gunmen opened fire on police escorting polio workers in Karak, a city in Khyber Pakhtunkhwa, killing one police officer and wounding a health worker.
The latest violence comes a day after Pakistan launched its final nationwide polio vaccination campaign for the year, aiming to protect 45 million children. According to the World Health Organization, Pakistan and neighboring Afghanistan remain the only two countries where the potentially fatal, paralyzing virus has not been eradicated.
Pakistan has reported 63 confirmed cases since January and the ongoing anti-polio drive will continue until Dec. 22.
Insurgents often target police and health workers during anti-polio drives.
More than 200 polio workers and police assigned for their protection have been killed since the 1990s, according to health officials and authorities.
