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Traffic had to be held temporarily for a short time after two cars crashed inside the Dartford tunnel this morning.
The incident involved the tunnels having to be closed. Earlier this morning the east bore structure was shut, before work started on the west bore tunnel, which was also closed.
Congestion had earlier reached the M25 anticlockwise between J1A A282 / A206 Crossways Boulevard / B3228 (Swanscombe) and J31 A1306 Arterial Road West Thurrock / A282 Dartford River Crossing.
Highways England tweeted around 11.15am to say all traffic had been released and was now flowing.
A spokesman said the accident took around 50 minutes to deal with.