An Afghan police official says six police have been shot and killed by colleagues who turned their guns on them at a checkpoint in the volatile southern Uruzgan province.

Mohammad Hasham, head of police in the Charchino district, says the shooting happened in the early hours of Saturday morning.

He says three officers involved in the shooting have escaped the scene, taking weapons and vehicles with them.

The incident follows another in the capital Kabul on Friday, when an Afghan security guard at a U.N. compound shot two Nepalese guards, killing one and wounding the other.

In southern Zabul province on Thursday, eight policemen were shot dead by a colleague. The Taliban, who have been fighting the Kabul government for fifteen years, are often behind such attacks.