Emergency services have been called to three collisions involving Range Rover, Toyota Yaris and an Audi s3 on the outskirts of Fareham.
Officers from Hampshire Police have closed the busy A27 between Fareham and Titchfield in both directions following the serious collision that happened just after 8pm on Monday evening near the Shell filling station.
Police have closed the road in both directions and drivers are being asked to seek an alternative route. Firefighters from Hampshire and Isle of Wight Fire and Rescue Service are also currently on the scene using specialist cutting equipment to help free a number of persons who are trapped.
Those involved are being treated by Paramedics from South Central Ambulance Service.
A critical care team from the Hamshire and Isle of Wight air ambulance have also been called to the scene, Please avoid the area whilst emergency services deal with the incident.