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.
Officers said the incident occurred shortly after 9.50pm on Sunday, as a grey Peugeot 508 headed east on Bletcham Way, Bletchley from the Denbigh roundabout.
A green Fiat 500 which had left the A5 at Caldecotte Roundabout was travelling in the opposite direction and the two cars collided, injuring a 30-year-old woman and a baby in the Peugeot.
The infant was taken to a nearby hospital where she died from her injuries.
The Fiat driver suffered a broken leg and was taken to Milton Keynes University Hospital for treatment. She has since been discharged.
A 27-year-old man from Milton Keynes was arrested on suspicion of causing injury and death by dangerous driving, driving while unfit through drink or drugs, driving 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.
Sergeant Ed Crofts, from Thames Valley Police’s Serious Collision Investigation Unit, said: Our thoughts are with the family of the child who has tragically died.
“I would like to appeal to anybody who was driving along H10 Bletcham Way at around the time of the collision to please contact Thames Valley Police, especially if you witnessed what happened or saw either vehicle being driven just prior to the collision.
“I would also ask drivers to please check dash-cam and get in touch if this has captured anything that may assist this investigation.”
Those with information can contact Thames Valley Police by making a report on their website or by calling 101, quoting reference number 43220546207.
Information can be given anonymously via the independent charity Crimestoppers on 0800 555 111.