Several people have died and four others have been taken to hospital after a motorway crash involving a minibus and two lorries, police say.
It happened on the southbound M1 at Newport Pagnell in Buckinghamshire just before 03:15 BST.
Thames Valley Police said the minibus was believed to have travelled from the Nottingham area.
Two men have been arrested on suspicion of causing death by dangerous driving and are in police custody.
The southbound carriageway is due to remain closed “for a significant amount of time” while emergency services work at the scene.
The vehicles were all travelling in the same direction between junctions 15 and 14, police said.