One appliance and crew from Broughton, two from West Ashland and one from Newport Pagnell attended, along with an officer.
A car had overturned, and was on its side on a verge, when they arrived.
One man and two girls were released from the car. The firefighters provided immediate emergency care, before passing them into the care of South Central Ambulance Service.
While they were at the scene a second car was involved in a collision. The firefighters released one man, injured, and provided him with immediate emergency care. He was also passed into the care of South Central Ambulance Service.
The road was closed while they worded at the scene.
National Highways and Thames Valley Police also attended.
