LOWER DIR: At least three people have been killed while 20 others sustained injuries as a passenger van plunged into a ravine in lower Dir. Sources said that a passenger van carrying more than 30 persons was on its way when it plunged into a ravine in the area of Asbaz. As a result, three people died on the spot while 20 others including women and children sustained serious injuries. Locals and rescue 1122 reached the scene and rescued the injured and retrieved dead bodies and shifted them to nearby local hospital for first aid and medico legal proceedings. According to police, preliminary investigation revealed that incident happened due to over speeding while further investigation is underway.