A seven-month-old baby girl was killed and a woman injured in a car crash in Milton Keynes.
Police have arrested a 27-year-old man on suspicion of driving under the influence of drugs or alcohol and continue to appeal for witnesses.
Shortly after 9.50pm on Sunday, a grey Peugeot 508 was travelling in an easterly direction along H10 Bletcham Way, Bletchley from the Denbigh roundabout towards Fenny Lock.
A green Fiat 500 was travelling in the opposite direction having come from the A5 Caldcotte exit when it was involved in a head-on collision with the Peugeot.
A baby travelling in the car was taken to a nearby hospital where she died due to her injuries.
The driver of the Fiat suffered a broken leg and was taken to Milton Keynes University Hospital for treatment, and she has since been discharged.
A 27-year-old man from Milton Keynes was arrested on suspicion of causing death by dangerous driving, causing serious injury by dangerous driving, driving while unfit through drink or drugs, and driving a motor vehicle with a proportion of a specified controlled drug above the limit and failing to stop after a road traffic collision.
He was released on bail while the investigation continues.