Four passengers were killed and 24 others were injured in an accident caused due to a collision between a truck and a State Transport (ST) bus in Jalna district Saturday evening. The ST bus, going towards Mahurgad from Malegaon, was carrying about 60 passengers. Officials said that it is suspected that the bus collided head-on with the truck after in a high speed, causing both the vehicle to mangle. Some passengers were rescued from the bus and rushed to the district government hospital. Officials said that a probe is on to determine the speed at which both the vehicles were being driven. Police are also in the process of recording statements of the passengers.