Firefighters were called to reports of a fire and explosion under the pavement on Mare Street in Hackney. It is believed that an electrical intake box under the pavement caught fire. Mare Street was closed in both directions from Morning Lane to Paragon Road.
Firefighters also set up a 25 metre safety cordon while crews worked with colleagues from UK Power Network. There were no reports of any injuries.
One fire engine and five firefighters and officers from Homerton fire station are at the scene.
The Brigade was called at 0933 and the incident was over for the Brigade at 1427. The cause is not known at this stage.