Two people are in a critical condition and eight others are suffering from varying injuries following a crash involving multiple vehicles near Oamaru.

Police rushed to the scene on State Highway 1 at Maheno around 6 pm to find people trapped in the vehicles involved.

Three helicopters were sent to the scene.

Initial reports from police said five people were injured in the crash. However, St John Ambulance confirmed 10 people had sustained injuries in the collision.

Diversions are in place for northbound traffic at the intersection of Fortification Road and State Highway 1, and southbound traffic is being diverted on Happy Valley Road at State Highway 1.