Two adults and a teenager died and a second child suffered serious injuries in a car crash on the M5 in south Gloucestershire.

A white BMW crashed at about 9pm on Friday when it left the northbound carriageway between junction 14 and Michaelwood services, Avon and Somerset police said. Officers believe no other vehicle was involved.

The two adults, both in their 40s, and teenager who were travelling in the car have died, while the second child was taken to hospital and was in a critical condition.

“Our thoughts first and foremost are with the child in hospital and loved ones who have received the most awful news overnight,” said Insp Mark Vicary of the roads policing unit.

“A specially trained officer will provide them with support at this difficult time. Emergency services have worked throughout the night at what has proved to be a very complex scene. They have worked diligently and professionally to try to save life in the most tragic of circumstances.”

The M5 is closed in both directions between junctions 14 and 13. Vicary said the closures were necessary because the vehicle still needed to be recovered. National Highways will need to assess the carriageway and possibly make repairs before the motorway can be deemed safe to reopen.

“As a result, the M5 remains closed this morning and we estimate it will need to stay shut in both directions for the next few hours, however, we are doing all we can to reopen it as soon as possible,” Vicary said.

“We appreciate this closure is causing delays and disruption to the public; particularly at the end of the half-term break. But given the severity of this distressing incident, we hope the public can understand the reasons why this is necessary and ask them to consider alternative travel plans.”