Sixteen people were killed in a collision between two buses on the R61 between Cradock and Graaf-Reinet in the Eastern Cape on Saturday, Arrive Alive said.

Arrive Alive spokesman Tshepo Machaea said that one of the buses was carrying schoolchildren to an event in Graaf-Reinet when it collided with a bus carrying passengers from Cape Town to Mthatha.

He said it was unclear whether the accident was a head-on collision or a side-swipe.

Four people were seriously injured and another 27 suffered slight injuries. All were taken to Cradock hospital for further treatment.

Machaea said the 16 were killed instantly and many of the injured were trapped in their buses until they could be cut free by rescue workers.