Nato raid 'kills Pakistan troops'

Three Pakistani soldiers have been killed in an attack by Nato helicopters during a cross-border attack, Pakistani officials say.

An unnamed Pakistani security official told the AFP news agency that the soldiers were killed in an "unprovoked attack" on a Pakistani checkpoint.
The Nato helicopters crossed up to 5km (three miles) into Pakistan, he said.
The strike was the third Nato raid across the border into Pakistan over the past week.