The Queen Elizabeth II bridge has been closed as multiple emergency services deal with an incident.
Essex Police said they responded to concerns for the welfare of a man on the bridge, which links junction 31 of the M25 at Lakeside/Purfleet in Essex and junction 1A of the M25 at Dartford in Kent.
The incident was reported shortly after 10:50 BST and a diversion was put in place using the Dartford Tunnels. Police said delays were expected to continue.
There have been queues of six miles on the clockwise M25 and four miles on the anti-clockwise carriageway, and motorists have been urged to avoid the area “wherever possible”.
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