Three people have been taken to hospital after a two-vehicle crash near Shepton Mallet.
The air ambulance was called in, and one of the vehicles involved caught fire after the collision just before 1630 BST on Wednesday.
It is believed that a motorbike collided with a car travelling in the opposite direction on the A361 at Doulting Hill.
Its rider and pillion passenger were taken to the Royal United Hospital, with possibly life-threatening injuries: one of them was airlifted from the scene.
Investigation
The driver of the car, believed to be a local man in his 40s, has also been taken to hospital.
He sustained injuries while trying to pull the rider and passenger away from the motorbike, which had caught fire.
Police, fire and ambulance crews all attended.
The road was closed for several hours but reopened after 2000 BST.