Gen Ghulam Sakhi Roghlewanai, police chief of Uruzgan province, said today another 11 policemen manning the checkpoint when the shooting happened last night are still missing.
He says it is still unclear what happened at the checkpoint, which is located on the highway between Kandahar and Uruzgan provinces. No group has claimed responsibility for the incident.
Afghanistan's police fight insurgents on the front lines, but have fewer resources than the army.
On remote checkpoints they are vulnerable to Taliban attacks. Authorities want to consolidate the checkpoints into larger bases but have faced resistance from locals who see them as a barrier against insurgents.