Two people are dead after a car and truck collided on the Kilmog on State Highway One, near Evansdale.

The crash happened just after midday on State Highway One just north of Dunedin killing two female passengers who were travelling in the car.

The driver of the car was airlifted to Dunedin Hospital with serious injuries. His condition is unknown. The driver of the truck wasn't injured in the crash.

The accident forced the closure of State Highway One... between Evansale and Karitane.

Police have been diverting traffic, and advising motorists to slow down and drive to the conditions.

Police are still investigating the cause of the crash.