A man has been arrested after the car he was driving crashed, leaving a woman seriously ill.
A silver Citroen Saxo and a grey Vauxhall Cavalier were involved in a head-on collision on the A36 between Salisbury and Wilton, Wiltshire, at 2329 GMT on Thursday.
The driver and the passenger of the Saxo, a husband and wife from the Wilton area, were taken to hospital, where the woman is in intensive care suffering serious chest injuries.
The driver of the Cavalier ran away from the scene. A man was later arrested in the Bemerton Heath area of Salisbury.
The driver of the Saxo and three people from the Cavalier were all treated at Salisbury District Hospital, but their injuries were not thought to be life-threatening.
Police closed the A36 for three hours while they examined the scene of the accident.
Anyone with information is asked to contact Wiltshire Police.