Several people have been seriously injured in a crash involving four cars that has blocked the M25.

Police and ambulance crews are on the scene of the collision on the anti-clockwise carriageway at junction 3 for the M20.

The crash happened at about 6.20pm, and a police spokesman said "serious injuries have been sustained."

Traffic is being diverted off the motorway at junction 4.

Two lanes are closed on the opposite side of the road due to damage to the barrier on the central reservation.

Police said the road could be closed until the early hours of the morning.