Three lanes are closed on the QE2 bridge following a crash.
Two cars have been in collision, causing delays back to J29 (A127).
Three lanes are believed to be closed on the bridge.
A spokesman from Essex Police said: "We have closed three lanes on the Dartford Bridge following a collision at around 2.20pm today, Monday, September 17.
"We received reports of a collision involving two vehicles. A man has suffered a serious injury, not believed to be life threatening or changing.
"We remain at the scene and will update you once we have more information.
"We thank you for your patience as we deal with this incident."
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