Essex police have arrested two lorry drivers on suspicion of dangerous driving following a multiple pile-up on the M25 near Lakeside.
One person was killed and five more including a child were taken to hospital following the crash involving three lorries and five cars.
The collision happened between Junctions 29 and 30 shortly before 12:30pm. A section of the clockwise carriageway has been closed with traffic being diverted off and back on the motorway. The road is expected to be closed until later on Tuesday evening.
One person has been killed and five people including a child have been taken to hospital after a crash on the M25 near Lakeside in Essex.
The crash involving three lorries and five cars happened around 12.30pm and the southbound carriageway is closed.
"Two patients have since been airlifted to the Royal London Hospital in Whitechapel with life threatening injuries. A further two adults and a child have been taken by land ambulances to Basildon Hospital for further treatment, their injuries are non life threatening."
– East of England Ambulance Service spokesman Gary Sanderson
Two air ambulances have been called a serious crash on the M25 near Lakeside in Essex. The East of England Ambulance service says the crash involves multiple vehicles including lorries.
"At present we have two ambulances, a duty officer, the Trusts hazardous area response team (HART), the Essex and Herts Air ambulance teams at the scene treating several casualties. Due to this, the Kent Air Ambulance has also been called upon to assist at the scene."
– Gary Sanderson, East of England Ambulance Service
Drivers are being advised to find alternative routes and avoid junction 30 of the M25.
The M25 anticlockwise is blocked with stationary traffic and long delays between J30 A13 (Lakeside / Tilbury) and J29 A127 (Romford), congestion to J1a A282 / A206 Crossways Boulevard / B3228 (Swanscombe).
A second air ambulance is attending the accident on the clockwise side and there are long delays whilst all traffic is held anticlockwise.
The Highways Agency are warning drivers that the M25 in Essex is closed anti-clockwise between J27 and J25 due to a serious incident involving a number of heavy goods vehicles.
A signed diversion is in operation with all traffic advised to leave the M25 anti-clockwise at J27 and follow the square diversion symbol via the M11, A406 and A10 to rejoin the M25 anti-clockwise at J25.
A second traffic alert has also been issued for motorists travelling along the A12 towards London, to be warned that there is a broken-down abnormal load vehicle close to J21, Witham.