An “enormous crash” which “wrecked” two vehicles on the M1 is causing heavy traffic just before Watford. 

The collision was on the northbound carriageway between junctions 4 and 5 and has forced two lanes to close.

Five cars and one heavy goods vehicle are thought to have been involved in the crash and around seven or eight vehicles were seen pulled over on the side of the road, at around 8.45am.

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Herts Fire and Rescue has confirmed one woman became trapped in a car and had to be released by firefighters, before being taken into the care of the ambulance service.

There are 40-minute delays according to Google Maps, with traffic building in both directions.

A passer-by travelling southbound described the crash as “enormous”, adding: "There were two wrecked cars, with about 7 or 8 pulled over, I don't know if they were involved or just helping.

Watford Observer: Traffic on the M25 after the crash. Pictures: National HighwaysTraffic on the M25 after the crash. Pictures: National Highways (Image: National Highways)

“There was a builder’s lorry which I think had parked to protect them and block the first two lanes.”

A Herts police spokesperson said: “Police were called at just after 8.30am.

“A blue Honda Jazz, a silver VW, a lorry, a green Land Rover, a red Vauxhall Astra and a grey Honda were involved.

"One person is thought to have suffered a shoulder injury.

“Two lanes were blocked by the incident and there are delays while the it is dealt with and vehicles recovered.”

Fire crews from Borehamwood, Watford, St Albans and Garston attended the crash.

National Highways told motorists to “expect long delays".

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