Police, firefighters and paramedics were called to Harvest Ride near the Quelm Park roundabout at about 7.35am this morning, where the three vehicles had collided with each other.
Two fire crews from Bracknell and Wokingham were sent to the scene, where they had to cut out two people from one of the cars.
The South Central Ambulance Service sent three ambulances, a rapid response vehicle, an ambulance officer, while Hampshire and Isle of Wight Air Ambulance service also sent a helicopter.
Four people were treated at the scene, including a man with chest pains. One of them was taken to Wexham Park Hospital, while three were taken to Frimley Park.
The road was closed by police on arrival and is still currently blocked off.
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