A serious crash has closed State Highway 79 (Geraldine–Fairlie Highway) near the intersection with Bracefield Road in South Canterbury.

Emergency services were called to the scene shortly after 11:25am, following reports of a collision involving at least two vehicles.

Two people have sustained serious injuries, while three others have minor to moderate injuries, a police spokesperson told Chris Lynch Media.

St John said two rescue helicopters, a rapid response unit, a PRIME responder, three ambulances, and an operations manager were dispatched to the scene.

A total of five patients were assessed: two in serious condition were airlifted to Christchurch Hospital, one in moderate condition was transported by ambulance to Timaru Hospital, and two with minor injuries were treated at the scene and did not require hospitalisation.

The highway is closed between Fairlie and Earl Road, and the Serious Crash Unit is investigating.

Detours are in place: from the Fairlie end via State Highways 8 and 1, and from the Geraldine end via Route 72, and State Highways 1 and 8.

Motorists are advised to avoid the area or delay travel where possible.