Six people – five men and a woman – have been arrested after a man was injured in a fall from a minibus on the M6.
The incident caused chaos on the motorway, which was closed for several hours between Lancaster and Galgate on Sunday afternoon.
A man, aged 39, who fell onto the carriageway from the minibus travelling northbound between junction 33 and 34, close to Lancaster University, suffered serious head injuries.
He was airlifted to Royal Preston hospital where he was in a stable condition, police said.
Five men, aged 48, 29, 34, 31 and 19, and a woman, aged 36, who were also travelling in the minibus were arrested by police on suspicion of assault and were in custody.
Police were called at around 1.50pm and the motorway was closed for several hours while emergency services attended the scene.
Detectives are appealing for witnesses following the incident and are urging anyone with dashboard mounted camera footage to contact police.
Det Insp Bev Mason, of Lancaster CID, said: “We are at the very early stages of our investigation and want to establish what has caused this man to fall from the vehicle.
“While we have made a number of arrests, we are appealing to anyone who saw what happened, or who has dashcam footage of the incident, to contact us.
“If you saw anything unusual which may help with our enquiries, call police.”
Anyone with information can contact police on 101 quoting log reference 0736 of September 3.