Police closed part of the M1 near Watford for about nine hours after a "serious accident" on Easter Monday night.
Emergency services attended the scene near Watford at about 9pm last night as they worked to help those involved and clear the scene.
Update: police have confirmed two people died at the scene, more information here.
Closures were in place southbound between junction 6A (M25/J21A) at Bricket Wood and junction 5 near Watford until about 6.30am today.
National Highways East said the closure was due to a "serious accident" and thanked queuing motorists for their patience.
Last night Herts Police said: "Motorists are asked to please avoid the area at this time."
Herts Fire and Rescue confirmed they had joined police and ambulance teams at the scene.
The road has now fully reopened.
More to follow.
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