PESHAWAR - At least five persons were killed and 34 others, including 25 personnel of the security forces, were injured on Friday when suicide attackers hit their explosive-laden vehicles with buildings at Kohat Tunnel , officials said. Meanwhile, some unknown militants also blew up a bridge on Indus Highway and attacked a security forces check-post in Darra Adamkhel. The officials informed that the convoy of three suicide bombers entered into Kohat Tunnel . When the security forces saw the first one, they fired at his vehicle and as a result his car exploded, killing him on the spot. While the second one hit his explosive-laden motorcar with Northern Building of Kohat Tunnel while the third one left his explosives-packed vehicle near Kohat Tunnel and escaped from the scene. Later, the security forces blew up the vehicle with shells. The identity of the suicide bombers has not been ascertained yet. The officials informed that five persons were killed while 34 others, including 25 security personnel, were injured in the incident.   Later, all the injured persons were shifted to Combined Military Hospital Kohat . Meanwhile, no loss of life was reported in the incidents of blowing up a bridge on Indus Highway and attacking a security forces check-post.