Officials in northwestern Pakistan say gunmen have attacked a polio vaccination center, killing a health worker.
Authorities say at least one other person was wounded in the attack Saturday on the outskirts of Peshawar, the capital of Khyber Pakhtunkhwa province.
No group has claimed responsibility for the attack.
Militants frequently attack polio workers in Pakistan, accusing them of being Western spies or part of a plot to sterilize Muslims.
The disease is highly infectious and can cause irreversible paralysis.
The Global Eradication Initiative says polio remains endemic in three countries - Afghanistan, Nigeria and Pakistan. The Initiative says until poliovirus transmission is interrupted in these countries, all countries remain at risk of importation of polio.