A reported two-car crash in the M25 is causing long delays as congestion remains in the M1 following an earlier collision.

National Highways confirmed that traffic was being held in the M25 anti-clockwise near Potters Bar, between junctions 23 and 24, early this afternoon. By 12.33pm traffic had been released, but two lanes remain closed as motorists passed the scene in lanes 1 and 2.

Herts Police are at the scene and have been contacted for more information on the crash. Multiple cars were reportedly involved.

Watford Observer: Earlier traffic camera picture of the scene.Earlier traffic camera picture of the scene. (Image: National Highways)

Google Maps is estimating delays of around one hour for motorists.

The road is expected to clear by 2pm and normal traffic is expected by 3pm, according to National Highways. The clockwise entry slip at junction 23 is closed.

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The road closure closely followed another Hertfordshire motorway closure, in the northbound M1 near Hemel Hempstead.

Delays remain for journeys between junctions 8 (Hemel Hempstead) and 9 (Flamstead) after three vehicles were reportedly involved in a crash.

One patient is confirmed as being treated by the East of England Ambulance service.