Officials say an unknown gunman has shot and killed a deputy counterterrorism official in western Farah province.

Mohammad Naser Mehri, spokesman for the provincial governor, says the gunman opened fire Thursday on Abdul Jalal's vehicle, killing him.

Mehri added the attack took place in the provincial capital, also called Farah, when Jalal was on his way home.

Mehri says police are investigating and no one has been arrested.

There was no immediate claim of responsibility by insurgent groups.