At least five people have been injured in a crash between a lorry and several cars on the M5 in Gloucestershire, the ambulance service has said.
The accident happened between junctions 10 and 11, between Cheltenham and Gloucester, shortly after 5pm on Tuesday.
The emergency services said at least one male driver had suffered life-threatening injuries, while two motorists were also taken to hospital and two others were assessed at the scene.
John Oliver, from the Great Western Ambulance Service, said: "We received the first of several 999 calls around 5.15pm reporting road traffic collision on the M5.
"Callers reported a lorry travelling northbound just past junction 11 collided with several cars - at least some of which were travelling southbound."
Gloucestershire Police said the accident affected both north-bound and south-bound carriageways and involved seven vehicles - a silver VW Passat, a blue MG, a grey Ford Escort, a silver Audi A4, a silver Ford Mondeo and a lorry.
"A white Renault van, that is thought to have been involved in the incident, was located on the exit slip road of the M5 northbound at junction nine and a man was arrested on suspicion of dangerous driving," a force spokeswoman said.
"The driver of one of the vehicles, a man, has been airlifted to Frenchay Hospital in Bristol with serious injuries.
"A female passenger in the same vehicle has been taken to Cheltenham General Hospital."