Officials in Pakistan say a police officer who was escorting polio workers in Khyber Pakhtunkhwa Province was shot dead by unidentified gunmen.
Health Department official Kamran Ali Afridi said on April 24 that the officer was killed in the town of Buner the previous day.
Another police officer was also shot and killed by unknown assailants in the northwestern district of Bannu as he was traveling to join a polio team. The motive for that incident is unclear.
Afridi also said two new polio cases have been reported in the northwest part of the country, despite the government's campaign to eradicate it.
Police also said a polio worker was stabbed in the city of Lahore after a heated argument with local residents. He was hospitalized.
Fundamentalist clerics and militants claim that government vaccination campaigns are part of a Western conspiracy to sterilize Pakistani children.
Pakistan, Afghanistan, and Nigeria are the only three countries in the world that still suffer from endemic polio, which can cause paralysis or death.
Based on reporting by Reuters and AP