The northbound M1 was closed near Watford this afternoon after an ambulance was called to the scene of a crash.

There were long delays as the motorway was completely shut northbound for a short time, between junctions five and six, just before 2pm.

It then had just one lane open for around 50 minutes.

An East of England Ambulance Service spokesperson confirmed one ambulance was sent to the scene of the crash, near junction 6, and one patient was assessed.

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The patient did not need to be transported to hospital.

National Highways warned motorists to expect between 15 and 30 minutes of delays, before it confirmed the road had cleared just before 3pm.

Delays on the M1 northbound (Image: Google Maps)

Traffic was queueing from Junction 5 and there was also knock-on traffic for the A41 towards Leavesden.

Delays on the M1 had mostly cleared by 3.10pm.

Hertfordshire Constabulary confirmed it was aware of the crash but did not attend as it was dealt with by highways and ambulance services.