Motorists travelling through Waikato are being urged to stay off the Taupiri detour following a serious crash.
Two people have been taken to hospital in critical condition after the car they were travelling in collided with another vehicle about 10.15am on Saturday.
The crash happened near Puketaha on the Taupiri detour, which is used as a shortcut by motorists travelling between Auckland and Cambridge to avoid Hamilton.
Police say motorists travelling north or south should stay on State Highway 1, while those driving east or west should remain on State Highway 26.
Crash investigators are at the scene, and the road is expected to remain closed for some time.