Drivers are being warned to avoid the M25 because of a "serious" crash.

All four lanes were blocked between j19 and j18 near Watford for more than half an hour.

However, the incident has now been cleared to the hard shoulder and the motorway is fully open.

A number of emergency services were called to the scene at around 9.30am this morning.

A number of drivers were spotted out of their cars as traffic was held in rising temperatures.

Traffic is currently queueing back to j21A for Bricket Wood on the M25.

It is also queueing to get on at j19 from the A41 roundabout and the A41 is stationary in both directions between j20 at the M25 and the Hunton Bridge junction.

Traffic is heavy anti-clockwise approaching the crash from j17 for Rickmansworth.

Delays are now expected to ease.