Johannesburg - Four people, including two children, sustained critical to serious injuries when a minibus taxi collided with a car on Randfontein Road in Roodepoort, west of Johannesburg on Tuesday morning, metro police said.Earlier information, where it was believed a taxi full of children had been involved in the accident, proved to be incorrect, Chief Superintendent Wayne Minnaar said."The passengers of the taxi weren't [all] children and four people were injured."The accident, which happened between Corlett Avenue and Nick Toomey Boulevard, has since been cleared with traffic running smoothly.Emergency service Netcare 911 said provincial and other services responded to the accident."Upon assessment of the occupants of both vehicles, paramedics found that the male driver of the minibus and female driver of the motor vehicle sustained serious to critical injuries," spokesperson Santi Steinmann said."Two children travelling in the motor vehicle sustained serious injuries during the collision."All four people were treated on scene and transported to hospital for further treatment.The cause of the accident was unknown.Police were investigating.