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
Julie Etchingham meets the original Foxy Lady - her cousin Kathy - who talks of life with former boyfriend Jimi Hendrix in their old flat.
Transport bosses have admitted a decision about funding for Luton's railway station's much-needed facelift will not be made any time soon.
A man who helped officers apprehend a suspected drug dealer by sticking out his foot and tripping him has been hailed a "legend" by police.