A man is critically ill after being dragged along a motorway as he clung onto his van trying to stop someone stealing the vehicle.

Police are treating the incident on the M602 outside Salford as attempted murder and have appealed for witnesses.

The 28-year-old victim had stopped on the hard shoulder to help a driver whose lorry had overturned on the slip road around 8.30am on Sunday.

Greater Manchester Police said the victim left the keys to his VW Caddy van in the ignition - but the lorry driver then jumped into his van and drove off, with the motorist holding on.

He was dragged for some distance along the motorway before he fell off and suffered serious head injuries.

The VW Caddy was driven onto the M60 towards Stockport but has not been found.

However, a 43-year-old man is in custody on suspicion of attempted murder.

Detective Sergeant Julie Connor from Salford CID said the man who was injured is in a critical condition in hospital.