A lorry fire on the M25 this afternoon has now been extinguished, but the anti-clockwise carriageway remains closed.
The blaze started just after midday between junctions 22 for the A1081 and 21A for the A405 near St Albans.
Fire crews from Potters Bar, Borehamwood and Garston have now put out the fire on the anti-clockwise carriageway.
Traffic was stopped on both carriageways at about midday. There are no reports of casualties.
Police said the road will be closed for several hours and warned motorists to plan alternative routes.