Four people have died after a road collision in Bedfordshire.
Police said the casualties had been confirmed following “highly complex work” by emergency services.
Officers were called at around 3.40am on Sunday to reports of a serious single-vehicle collision near the Flying Fox roundabout on the A5.
Emergency services attended after reports of a car alight in a field close to the village of Heath and Reach, near Leighton Buzzard.
Bedfordshire Police said a man who had been travelling in the car was pronounced dead at the scene.
On Monday, officers confirmed three other people travelling in the car had also died.
Investigators are appealing for witnesses with dashcam footage who may have information about the incident.
They said work at the scene is likely to continue into Tuesday.
Acting Sergeant David Burstow, from Bedfordshire, Cambridgeshire and Hertfordshire Serious Collision Investigation Unit, said: “We are doing our work in a dignified and meticulous manner in order to establish what happened in this tragic, awful incident.
“We believe there were four people in the car who sadly died in the collision.
“Specially trained officers are speaking to their families and are offering them support, while forensic identification is still to take place.
“While we believe no other vehicles were involved. Our investigations are ongoing into the circumstances surrounding the incident.
“At this point we are keen to reiterate the requests of the families involved not to speculate on social media, but I would appreciate any information from witnesses or anyone else who may be able to assist us with our inquiries.
“We would be particularly interested to hear from anyone with dashcam or CCTV footage which could help with our inquiries.”
Anyone with any information can contact Bedfordshire Police through the online reporting centre or call 101, quoting Operation Loddon.