A multi-car collision has closed the M25 up to St Albans.

No traffic can currently travel along the clockwise carriageway between junctions 19 and 21 or the anti-clockwise carriageway at junction 20.

Herts police are currently dealing with the incident near Watford, which they describe as “serious” and involving at least two vehicles.

Traffic is being diverted via the A41 and A405, to leave at junction 19 and rejoin the M25 at junction 21a, and Highways England is estimating an hour delay for drivers.

Any witnesses to the collision who have not yet spoken to police officers should call 101 with reference ISR 290 of March 27.