Police were called at approximately 12.45 today following reports of an electrical explosion on a building site at the junction of High Holborn and Drury Lane.
Officers, London Fire Brigade and London Ambulance Service are in attendance. One man believed to be in his 20s is being treated at the scene.
The Health and Safety Executive will be notified.
Road closures remain in place.
More top news
Six people were injured after they were hit with the substance during an "altercation" between two groups at a shopping in east London.
Save Your Uber in London was set up after it was announced the firm would not have its licence renewed when it expires next week.
Survivors are still traumatised, homeless and want answers.