Police want witnesses after four people were injured in a serious accident.

A silver Mercedes C Class car with a French number plate swerved off the road, went down an embankment and came to rest on a footpath.

The crash happened on the coast-bound stretch just before the Darenth Interchange at around 4.50am.

The air ambulance was sent to the scene, and a man - one of the passengers - was taken to a London hospital in a serious condition.

Three others were taken to a local hospital.

The road was closed until around 10.15am, when one lane reopened. Two lanes remained shut until just before 1pm.

The closure caused long delays for drivers, but congestion has now eased.

Police are now asking any witnesses, who have not already spoken to an officer, to call 01622 798538 quoting DS/MS/098/17 or email sciu.td@kent.pnn.police.uk.