A suicide attack has killed at least five Pakistani troops in the country's northwest.

Police say the bomber rammed an explosives-laden vehicle into a paramilitary building in the Bannu district of Khyber-Pakhtunkhwa province on Saturday.

At least a dozen members of the paramilitary Frontier Corps were wounded in the blast, which targeted the camp office of a unit called the Tochi Scouts.

No one has claimed responsibility for the attack.