At least four persons including three members of a family were killed and eight others injured in a head-on collision between an ambulance carrying dead body and passenger bus here in Vehari on Wednesday. According to police an ambulance carrying dead body from Bahawalpur to Karampur collided head-on with a reckless driven speedy passenger bus at Mailsi Road. As a result of accident four people including three of the same family were killed on the spot while eight others sustained injuries. The police and rescue personnel reached the scene of the accident and shifted the bodies and injured to Mailsi Hospital where according to hospital sources condition of three injured people was serious. The police took both vehicles into custody and started investigations.