Gunmen have killed a district governor and his son in Afghanistan's eastern Paktika province.

Abdul Raouf Massoud, a provincial police official, said the attack took place Sunday in the district of Shakhil Abad when Ajmal Khan was fired on in front of his house and both he and his son were killed.

Police said it was not clear who was behind the attack and no one immediately claimed responsibility.

Paktika is a remote province near the border with Pakistan where insurgent groups including the Taliban are active.