A man has died after being struck by several cars on the M66 motorway.
Greater Manchester Police said they were called to reports of a collision between junctions two and three at around 1.57am on Saturday.
Officers found a man who had suffered fatal injuries as well as four damaged vehicles.
The force said it appears as though the man was walking along the lanes of the motorway, and was struck by an Audi A5 heading northbound.
He was then struck by three vehicles travelling on the southbound carriageway and was declared dead at the scene.
A 19-year-old man has been arrested on suspicion of driving under the influence and remains in police custody.
Sergeant Helen Hallworth, of the Serious Collision Investigation Unit, said: "We believe we have identified this man and we have now spoken to his next of kin.
"However, we still need witnesses who may have seen this man walking up the motorway to contact us as a matter of urgency.
"As ever, any dashcam footage would be gratefully received, but at this stage any information from eyewitnesses would greatly help us with our investigation into this man's tragic death."
Police are asking anyone with information to call 101 or Crimestoppers on 0800 555 111.