Civilians shot dead by Pakistani security forces

At least two civilians, one of them a woman, have been killed by firing from security forces in north-west Pakistan, officials say.

They say that the incident happened in the tribal region of Darra Adamkhel, when troops fired at two passenger buses that were breaking a curfew.

It took place hours after a prolonged clash with militants in the same area.

Meanwhile the Taliban are suspected of blowing up a school in the Mohmand tribal region.

Reports say much of the school was destroyed after being repaired following previous attacks.

According to officials, about 40 schools, dispensaries and other government buildings in Mohmand region have been blown up by militants during the last year.

Search operation

The BBC's M Ilyas Khan in Islamabad says that incidents of Pakistani forces killing civilians by accident are rare.

On Wednesday night, more than 50 militants armed with heavy weapons attacked a checkpoint on the border between Darra Adamkhel and the north-western city of Peshawar, a local official told the BBC's Urdu service.

The security forces returned fire, sparking clashes that continued all night, he said.

On Thursday morning, the security forces imposed a curfew on the road through Darra Adamkhel and started a search operation.

Officials say the two buses were presumably unaware of the curfew.