The gunmen also set the forest department's flatbed truck on fire.

There was no immediate claim of responsibility from any group and police investigators said they were seeking investigating.

Mansehra borders the restive Malakand region, where the military is conducting a two-month offensive against the Taliban that the government claims killed more than 1,600 insurgents.

Most of the revenge attacks by the militants have been carried out on the troops, but police also became occasional targets.