Thick smoke shuts M25 over 'explosion risk' as firefighters battle to bring large industrial blaze under control

Thick plumes of smoke were seen rising over the motorway between junctions 21a and 22 of the M25 in Hertfordshire on Tuesday morning.

Ten fire engines were in attendance as firefighters continued to battle the flames and bring the blaze under control well into Tuesday afternoon, after calls were made to emergency services shortly after 9.21 am today.

The closure was described as a "precaution" by Hertfordshire Fire Service, with National Highways warning of "a risk of a secondary explosion, along with smoke and debris affecting the carriageway."

The fire is believed to have started on the Ventura Park site, with smoke visible for miles around.

Deputy Chief Fire Officer Mark Barber said: “We are currently responding to a fire at a large industrial unit in Ventura Park, Old Parkbury Lane, Colney Street, St Albans.

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"Fire Control has received a significant number of calls regarding this incident, and I would like to reassure residents that firefighters are working hard to bring the situation under control.

“Our firefighters have been working alongside colleagues from London Fire Brigade to bring the fire under control, and have successfully contained the fire within the unit.

"Crews are continuing to tackle the fire, but we expect it to be several hours before it is extinguished.As a precaution, we are asking people living nearby to keep their doors and windows closed and to avoid the area while emergency services continue to deal with the incident.

"I would like to thank the public for their patience, understanding and cooperation. Please continue to follow our advice and avoid the area to allow emergency crews to work safely and effectively."

The closure impacted rush hour traffic, as the fire brigade warned locals to keep doors and windows shut.

It comes as footage of the incident shot by commuters shows a thick plume of smoke rising into the air above the motorway.

It has not been confirmed how long the motorway closure will last, with emergency services warning drivers to allow extra time for their journeys.

"As a precaution, we are asking people living nearby to keep their doors and windows closed and to avoid the area while emergency services continue to deal with the incident," Mr Barber added.

"I would like to thank the public for their patience, understanding and cooperation. Please continue to follow our advice and avoid the area to allow emergency crews to work safely and effectively."

Hertfordshire Constabulary said in a statement: "The M25 is currently closed between junction 21a and 22 in both directions, due to smoke from a warehouse fire in Colney Street in St Albans .

"Road closures are also in place in Colney Street and Old Parkbury Lane. Officers and the fire service are at the scene.

"Motorists are advised to avoid the area and seek alternatives routes at this time. Local residents are advised to keep windows and doors closed at this time."