Around 11:45am today, the Electrical sub station on Blackbird Avenue caught fire as a pillar of smoke reached up into the air, being seen from as far away as De Montfort University.
The black smoke was seen throughout the city, with a number of places, including houses, losing power for nearly an hour. The police have cordoned off the area and are restricting access for safety reasons.
A spokesman for Leicester Fire and Rescue has said that the power cut has affected 45,000 homes in the area and that firefighting has started with two crews tackling the blaze with foam lines.
An officer on scene, said that there is no current indication of what has caused the inferno and that no one was hurt in the outburst of flames.
The sub-station contains 8,000 litres of insulating oil which is currently what is causing the fire and thick black smoke. Leicestershire Police took to Twitter to appeal to people in the area to keep their windows and doors closed.