Holborn fire: Smoke fills London streets and workers flee offices as blaze breaks out under Kingsway

Thousands of people were today forced to flee office buildings as police declared a "major incident" after a fire broke out under a central London street.

About 2,000 office workers were ordered to evacuate buildings due to the blaze, which started shortly after midday.

The London Fire Brigade (LFB) said it was called at about 12.40pm to a blaze in Holborn thought to have been caused by a faulty electrical junction box beneath the street. Police said the fire was being treated as a "major incident".

Pictures from the scene showed smoke billowing from an manhole cover on Kingsway, with firefighters having cordoned off the area.

Shortly after 3pm, LFB said: "Around 2,000 people evacuated from buildings near cable fire on #kingsway. Crews waiting for power to be switched off."

On Twitter, members of the public reported chaotic scenes as people poured on to the street and power cuts hit office buildings.

James Macfadzean tweeted: "Fire burning so quickly - whole area engulfed."

Jordan Hatch wrote: "Holborn is chaos. All the manholes on Kingsway are smoking."

Anne Bergeron said: "It's chaos on Kingsway Holborn, hope no one hurt."

Jenni Graham posted: "Fire at offices on Kingsway near Holborn in central London. Power cuts at nearby buildings. Several fire trucks."

LFB's assistant commissioner Peter Cowup said: "Crews are currently working to prevent the spread of the fire to surrounding buildings.

"As this is likely to be an electrical fire we have to ensure the power is off before we apply water to extinguish it.

"We are working with our partners and implementing well-rehearsed plans to prevent the fire from spreading and to protect surrounding properties."

UK Power Networks, the electricity provider, is on the scene, as are police and about 70 firefighters. The cause of the "power cable fire" is not expected to be identified today.

Kingsway was this evening shut between Holborn and Aldwych, while the Strand Underpass is also closed and Waterloo Bridge is closed northbound. Bus routes 1, 59, 68, X68, 91, 139, 168, 171, 188, 243, 341, 521 and RV1 are affected and commuters are advised to avoid the area altogether where possible.