A 28-year-old man is in a serious condition in hospital following a car crash on Tuesday.
The collision occurred on the northbound carriageway of the V4 Watling Street between the H8 Standing way and the H7 Chaffron Way at about 4.40pm.
A grey Nissan Micra travelling towards the H8 collided with a blue Nissan Qashqai which was travelling in the opposite direction.
The driver of the Qashqai, a 35-year-old woman, and the passenger, a young boy, were treated by paramedics at the scene and taken home with minor injuries.
The driver of the Micra, a 28-year-old man, and the passenger, a 25-year-old woman, were taken to Milton Keynes General hospital for treatment.
The woman has since been discharged but the man is still in hospital where his condition is described as serious but stable.
PC Phil McGlue said: “I would appeal to anyone who witnessed the collision or saw either vehicle prior to the incident to contact me via 101 and quote reference number 996 (21/4).”