Holborn station has reopened following reports of a “loud bang” and smoke filling the platform.
Commuters shared shocking videos of smoke filling the platform shortly before 9.30am.
British Transport Police said that the station was evacuated while firefighters investigated the incident.
BTP said that a defective train was the cause for the evacuation from the underground station this morning.
Witnesses also reported hearing a “loud bang”.
London Fire Brigade (LFB) said in a statement: “Two fire engines and 10 firefighters are investigating reports of smoke on platform at Holborn underground station this morning.
“The station has been evacuated.
“The brigade was called at 9.09am. Fire crews from Soho fire station are at the scene.”
The LFB later added that “it was an overheated compressor on a train not a fire.”
The fire service said it dealt with the incident in under 50 minutes.