At least six people are being treated following the incident, according to reports.

Police and paramedics were called to the M40 northbound in Oxfordshire between junctions 10 and 11 just before 11.40pm on Saturday.

In a video sent to Express.co.uk, Dan Mitchell showed the size and scale of the incident and the deluge of traffic it has created.

He said: “The tailback is a good mile long, I gave up on recording that.. the police presence is unreal there’s still a steady flow of blue lights going down there, they’ve totally closed J10 slip-road now.”

Thames Valley Police have warned travellers to avoid the area in a post on Twitter.

They stated: “The northbound carriageway of the M40 between junction ten and junction 11 is currently closed after a multi vehicle Road Traffic Collision.

“We would advise motorists to avoid the area at this time while emergency services are at the scene.”

Twitter user Scott Thorne stated that cars on the road are being asked to turn around.

He posted: “We’ve all been told to turn the cars around and leave the motorway waiting to be escorted now, terrible accident and my thoughts go out to the family’s involved.”

South Central Ambulance Service stated five crews were at the scene.

Traffic England said the motorway has been closed in both directions.

Highways England have said normal traffic conditions are expected to return “between 04.15 and 04.30” due to an “overturned vehicle”.

A South Central Ambulance Service spokesperson said the casualties went to hospitals in Oxford and Banbury.

In their latest statement, Highways England declared the road remains closed.

It read: “The M40 in Oxfordshire remains closed northbound this morning between J10 (Baynard’s Green) and J11 (Branbury), due to a serious traffic collision which occurred shortly before midnight.

“The response is being led by Thames Valley Police with the carriageway expected to remain closed for a number of hours and Highways England resources are assisting the police.

“A signed diversion is available from J10 following the ‘hollow black diamond symbol’, taking the A43 heading northbound towards Brackley.

“At Brackley road users meet the A422 roundabout and taking the first exit left, traffic joins the A422 to continue northbound to re-join the M40 at J11.

Road users are advised to allow extra time and may wish to consider alternate routes.”