One person is dead and State Highway One south of Levin remains blocked after a two-car crash this afternoon.
The crash happened just before 5pm in Ohau, south of Levin.
Two other people have been flown to hospital from the crash. One has critical injuries.
Diversions are in place, but police are warning people to expect significant delays.
Meanwhile there has been a second serious crash on State Highway 1 in Horowhenua.
The police say a truck and car have collided in Manakau and the road is blocked.
Motorists are being urged to avoid the area.