Pakistani police said on December 12 that an officer who was guarding a polio vaccination team in the northwestern town of Tank has been shot dead by militants in the second such deadly attack there in two days.
The Pakistani Taliban claimed responsibility for the previous day's attack, which killed one police officer and injured another.
In the second incident, gunmen fired on police as they were accompanying health workers conducting the door-to-door inoculation campaign on the morning of December 12, killing one officer.
Noor Aslam, a local police official, told RFE/RL's Radio Mashaal that the attackers fled the area and a “search operation is under way."
No group has claimed responsibility for the second attack.
The December 11 shooting took place two days after the Tehrik-e Taliban Pakistan (TTP) militant group declared an end to a monthlong cease-fire amid peace negotiations with the government.
Militants in Pakistan often target polio teams and security officers assigned to protect them, claiming the vaccination campaigns are a Western plot to sterilize children.
In October, a police officer guarding a polio vaccination team was shot dead by two TTP militants riding on a motorbike in Dera Ismail Khan, in northwestern Khyber Pakhtunkhwa Province.
In September, an officer escorting a vaccination team was also shot dead in the city of Kohat in northwestern Pakistan.
Polio is an incurable disease caused by a virus that usually travels from the gut to the nervous system, causing paralysis and death.
Pakistan and Afghanistan are the only two countries in the world where polio is still considered endemic.