Drivers are being urged to avoid the A148 at the junction for Castle Rising after a collision has closed the road in both directions.
Police and fire crews are at the scene near Hillington after the crash was reported to them shortly before 5pm.
Officers from the roads policing team and King's Lynn are on the scene as well as the ambulance service after two vehicles collided.
Fire crews from Kings Lynn, Massingham and Heacham attended and have released two casualties using hydraulic rescue equipment.
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