Tailbacks of up to 15 miles are frustrating commuters on the M25 this morning after a security alert at the Dartford crossing.

Toll booths for both the river and tunnel crossings have been closed, causing massive congestion on London's orbital motorway.

Traffic queues at the northern end of the crossing, situated on the Essex-Kent border across the Thames, were stretching as far back as the M11 junction at 9.30am.

Police are advising drivers to delay their journeys, find alternative routes, or face long hold-ups while the situation is remedied.

Kent Police said the alert had been raised by a member of the crossing staff at 8.10am after he had noticed a suspicious package by one of the toll-booths.

The bomb disposal squad has been called and they were assessing the situation at 10am today.

A spokesman advised drivers to avoid the area and said motorists should tune into radio traffic bulletins for the latest updates.

Converted for the new archive on 19 November 2001. Some images and formatting may have been lost in the conversion.