A coach carrying schoolchildren had its roof partially torn off in a multiple vehicle crash on the M25 today.
The accident, along with a second crash on the approach to the Dartford Tunnel in Kent, was expected to cause severe congestion in the area.
Police officers are at the scenes of both incidents and have warned of congestion on the M25 and surrounding roads in Kent.
The first accident involving the coach took place on the M25 close to junction four near Bromley, Kent.
The multiple vehicle crash involved two lorries, a coach and three cars on the anticlockwise carriageway.
Dramatic pictures show a lorry cabin having crashed into the back of a trailer, which in turn made contact with the rear of the coach.
The force from the collision was so powerful that the trailer even tore off part of the coach's roof.
The carriageway has been closed at junction 4 and all traffic is being directed to leave using the slip-road.
An air ambulance is attending due to injuries reported to one of the drivers.
A number of school children and teachers were on the coach but are reported to have no physical injuries.
The school is aware and is updating parents and drivers are advised to expect delays and avoid the area if possible.
One Twitter user reported that drivers were obstructing ambulances by driving on the hard shoulder.
The second crash happened on the A282 Dartford Crossing approach road which the M25 feeds into.
Others took to social media to voice their frustration over severe delays.
Max Elliot commented: 'Been stuck on the m25 going towards for 5 hours now. Any chance anyone will drop us some food off?'
Officers are currently at the scene of the accident involving a lorry, van and motorbike on the Essex-bound carriageway.
The carriageway has been closed at junction 2 and a diversion is being put in place to allow traffic to re-join the A282 at junction 1B.
Highways crews are working with our officers to free vehicles that are stuck in the queue after junction 2 but prior to the collision.