Several people have died and four others have been taken to hospital after a motorway crash involving a minibus from Nottingham and two lorries, police say.
It happened on the southbound M1 at Newport Pagnell in Buckinghamshire just after 3am.
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.
Highways England said traffic trapped between junctions 15 and 14 was being released past the scene, and diversion routes were in place from junction 15, with traffic following the A508, A5 and A509 to rejoin the M1 at junction 14.