The attack took place on the outskirts of Peshawar, the capital of the North-West Frontier Province, police officer Amanat Ali said.

Troops exchanged fire with an unknown number of attackers for more than hour after the attack, Ali said. One militant was injured, two were arrested and others managed to flee, the officer said.

Militants regularly target trucks and tankers in Peshawar, a key supply route for Western forces battling the Taleban in landlocked Afghanistan.