Eight fire engines and around 60 firefighters responded to a fire near Rhodeswell Road, Mile End.
An extension building of two floors, attached to a railway arch, was alight. The fire was located on both floors of the building, which is used as an office space. Firefighters will remain on scene into the morning, working to extinguish remaining pockets of fire. There are no reports of any injuries
Commuters should check with C2C for updates to rail services.
The Brigade was first called about the incident at 0353, and crews from Poplar, Millwall, Shadwell and surrounding fire stations were sent to the scene.Crews had the fire under control by 0549.
The cause of the fire is not yet known.