Six fire engines and around 40 firefighters rushed to Elephant and Castle Station last night after reports of a fire.
The London Fire Brigade was called at 11.11pm and fire crews from Dowgate, Lambeth, Old Kent Road, Dockhead and Peckham fire stations attended the scene.
They investigated the cause of smoke coming from a tunnel and determined it was caused by overheating in an insulating pot. Insulating pots are small devices which insulate the electrified rail. The incident was over by 1.30am.
Station Commander Keith McDermott, who was at the scene, said: “Firefighters investigated smoke coming from a tunnel and determined that it was caused by overheating in an insulating pot.
“Trains stopped running through the station whilst crews worked to make the scene safe. There were no reports of any injuries.”
There are currently no reports of disruption on the Northern Line passing through Elephant and Castle Underground Station.