One person died and a number of people were injured after two trains collided in the Bedford area, according to British Transport Police.
Air ambulance helicopters were on the ground after the collision happened just south of the Elstow interchange.
The prime minister, Keir Starmer, wrote on X: “Hugely concerning reports of a collision involving two passenger trains near Bedford. First and foremost, my thoughts are with the family of the person who has sadly lost their life, and with those who have been seriously injured. “I am grateful to the emergency services for their swift response to this tragic incident.”