At least four people were killed and 25 injured on Friday when a trailer and a passenger bus collided in Muzaffargarh. The accident occurred apparently due to over-speeding. Police personnel and Rescue teams immediately reached the site of the accident and shifted the casualties to Nishtar Hospital in Multan. Five of the injured were in critical condition, according to hospital sources. Pakistan has one of the world's worst records for fatal traffic accidents, blamed on poor roads, badly maintained vehicles and reckless driving.