One person has been killed and two others seriously injured in a crash involving a coach and a lorry.
West Midlands Police said 20 other people on the coach suffered minor injuries in the accident near Frankley Services on the M5 in the West Midlands.
West Midlands Ambulance Service said a large number of resources had been sent to the scene on the southbound carriageway of the M5 between junctions three and four.
A spokesman for the ambulance service said several ambulances, rapid response vehicles and a hazardous area response team had been deployed to the incident along with doctors and ambulance officers.
The spokesman said a number of patients were currently being conveyed to various hospitals across the area.
"Whilst the majority of patients appear to be walking wounded there are a small number with potentially serious injuries," the spokesman added.
West Midlands Police said no children had been involved in the accident and confirmed that the driver of the lorry was among those seriously injured.
The affected stretch of the M5 is likely to remain closed in both directions for a considerable time and motorists are being advised to find alternative routes.
Eye witness Paul Guppy told BBC News that there were fog patches on the motorway at the time of the crash. He was driving on the opposite carriageway at about 6.40am.
"There were fog patches, because I was driving through it with my fog lights on. That area is renowned for having fog, there's a lot of low-lying land," he said.