Four people are in hospital after a road accident, including a man with life-threatening injuries.
Wiltshire Police said a BMW collided with a black Toyota Verso on the A30 at about 18:00 GMT on Friday.
The BMW driver, a man in his 40s, was taken by air ambulance to Southampton Hospital.
The Toyota driver, a woman in her 40s, and her two child passengers were taken to Salisbury Hospital with serious injuries.
Wiltshire Police said it wants to hear from anyone who witnessed the collision, which happened near Shaftesbury, or has dashcam footage.