More than 30 people were injured when a Translux bus overturned on the N-9 main road in the Karoo on Tuesday morning.
The accident happened between Graaff-Reinet and Aberdeen but there were no reports of fatalities.
Provincial traffic department spokesperson, Tsepo Machaea says 24 passengers were injured, five of them critically while eight are in serious condition.
A passenger on the bus reportedly said they had earlier been transferred from a City to City bus which had experienced mechanical problems to the Translux Coach.
The cause of the accident is under investigation.