A 17-year-old girl has died after fleeing a police vehicle and being struck by a car on a motorway.

The girl was being transported to custody when officers stopped the Avon and Somerset Police vehicle while heading northbound between junctions 25 at Taunton and 24 at Bridgwater in Somerset.

She got out of the stationary vehicle and was hit by a car on the southbound carriageway shortly after 11pm on Monday.

Paramedics attended the motorway within minutes but the girl was pronounced dead at the scene.

Avon and Somerset Police made a mandatory referral to the Independent Office for Police Conduct (IOPC), which is now investigating the incident.

Detective Chief Superintendent Rachel Shields said: “Our thoughts are first and foremost with the girl’s family.

“Overnight we have updated her next of kin regarding what has happened and we will ensure they are supported by specially-trained officers at what is an incredibly difficult time following the tragic loss of such a young life.”

The IOPC has decided to take on the investigation independently, and we welcome the oversight it will give

Ms Shields added: “We believe it is important that we are as transparent as possible at this early stage about the tragic circumstances.

“A critical incident was declared and our Professional Standards Department notified overnight.

“A mandatory referral has been made to the IOPC, on the grounds of a death following police contact.

“The IOPC has decided to take on the investigation independently, and we welcome the oversight it will give.

“We recognise this incident has had a significant effect on the devastated officers, plus members of the public, who witnessed what happened, as well as other officers and staff involved in our response.

“We will ensure staff are able to access any welfare support they may benefit from following this tragedy.”

The motorway was closed in both directions while investigations took place.

National Highways said it had been fully reopened shortly after 11am on Tuesday.

In a statement, the IOPC confirmed that the police watchdog was investigating the incident.

A spokesperson said: “We have started an investigation into the circumstances surrounding the death of a 17-year-old girl who was struck by a vehicle on the M5 near Taunton last night.

“We were advised by Avon and Somerset Police that the girl was being transported to custody in a police vehicle and had got out of the vehicle shortly before the collision.

“We sent our investigators to the police post incident procedure to begin gathering evidence.

“Our sympathies are with the girl’s loved ones and everyone affected by her death.”

Anyone who witnessed the collision or has dashcam footage is asked to contact Avon and Somerset Police on 101, with the log number 1170 of November 11.