Twenty people were killed in two separate collisions in Mpumalanga and Limpopo on Friday.Fourteen people were killed in the one crash, which involved four vehicles on the N4 between Mbombela and Malelane.Department of Community Safety spokesperson Joseph Mabuza said: "The toll is now at 14, but it might change because we are still at the scene and people are still trapped. We are just doing a head count, but you might find others under the seats," Mabuza said.He said two trucks, a sedan and a 22-seater bus were involved in the collision.The cause of the accident is still unknown.Earlier, at around 19:00, six people were killed in a head-on collision on the N1 in Modimolle, Limpopo police spokesperson Brigadier Motlafela Mojapelo said. "It was a head-on collision involving two vehicles. It happened at about 19:00," he said.Mojapelo said three other people were seriously injured.He added that circumstances surrounding the cause of the crash were being investigated."Information is still sketchy, we are still waiting for more information," he added.