Insurgents killed at least seven people in an assault on a power station in north-western Pakistan on Tuesday, police said.

Four civilian guards were also missing after the militants used guns and grenades to attack the plant in Budh Bher, a suburb of Peshawar, capital of the restive Khyber-Pakhtunkhwa province.

“A policeman and a civilian guard suffered fatal injuries in the initial raid, while five bodies with gunshot wounds were found in a field about a kilometre from the facility,” police officer Granullah Khan said.

The five bodies appeared to be those of two policemen and three employees of the state-run utility service, taken hostage during the raid and then killed, he said.

Mr Khan said the gunmen destroyed the control room and set fire to vehicles parked inside the compound.

Details of the attackers, including their number or their affiliation, were not immediately available.

Budh Bher, on the outskirts of Peshawar, sees frequent attacks blamed on Pakistani Taliban, based in the adjoining tribal region bordering Afghanistan.