Two people were trapped after an apparent head-on collision in Timaru.
A police spokesperson said there were five occupants in the cars, two of which were trapped.
St John spokesperson Ian Henderson said two patients with serious injuries, two with moderate injuries and one with minor injuries have been transported to Timaru Hospital.
Fire fighters have now freed the pair.
Police said all emergency services were in attendance at the crash that happened on the Timaru-Temuka highway between Arowhenua Station Rd and Arowhenua Rd.