M25 fatal crash: Two men arrested over Waltham Abbey collision
Two men have been arrested in connection with a "catastrophic" crash on the M25 which left one person dead and several trapped in their vehicles.
The motorway was closed for more than 12 hours in both directions after four lorries and a car crashed near Waltham Abbey, Essex, at about 01:50 GMT.
A man, believed to be 39 and from Leicester, died at the scene.
Two men, aged 33 and 25, were arrested on suspicion of causing death by dangerous driving.
They are both being treated in hospital and will be questioned later.
Ch Insp Jonathan Baldwin, of Essex Police, said the crash site was a "catastrophic scene of carnage".
Four people were taken to hospital with injuries "which are not believed to be serious", the force said.
The Highways Agency said two lanes had opened in both directions between junctions 25 and 27, and the road had fully reopened between junctions 23 and 25. Some speed restrictions are in place.
But a spokesman said one lane would be closed in each direction until at least Wednesday morning, so repairs could be carried out.
It said a lorry had crashed into the central reservation and collided with vehicles travelling in the opposite direction.
Earlier, Insp Dick Thomas said: "We have one confirmed fatality and a number of people who [were] trapped in their vehicles.
"There is debris across both sides of the M25 and the motorway will be closed for the foreseeable future, while we deal with this collision and begin our investigations to establish what has happened."
BBC Essex reporter Stuart Woodward said traffic was "bumper to bumper for at least 10 miles" on the A414, from Norton Heath towards the M11, as people tried to find an alternative route during the morning.
There was a second serious crash in Essex shortly after 07:30 GMT, on the A120 near Coggeshall.
Essex Police initially announced that someone had died, but later said a woman was cut free from her vehicle and taken to hospital.
"She is not believed to be in a life-threatening condition," a spokesman said.