At least four people have died in a crash on the M5, police have said.
Emergency services were called just after 14:30 BST to junctions 15 and 14 in South Gloucestershire to a collision involving several vehicles including a lorry.
The motorway is closed in both directions and Avon and Somerset Police said it would be shut “for a considerable amount of time”.
The force asked drivers to avoid the area.
Highways England warned of “long delays” and said there was a six-mile queue northbound between junction 18 for Avonmouth and 16 for Almondsbury.