Severe delays are expected on the M25 "for some time" following a crash that closed the Dartford Tunnel.

Nine miles of traffic is tailing back on the London-bound carriageway after the accident in the west tunnel.

The tunnel was reopened at about 7pm.

But Highways England says "severe delays will remain for some time".

Writing on Twitter at about 7.10pm, a spokesman said there are nine miles of congestion on the M25 "which will start to ease soon".