More than 70 firefighters are tackling a "substantial" blaze at a row of shops in Yorkton Street, Hackney.
Thick black smoke is clouding the area and nearby residents are being advised to keep their windows and doors closed.
Ten fire engines and 72 firefighters from Soho, Islington, Holloway, Shoreditch, Homerton, Bethnal Green, Whitechapel, Tottenham and Poplar fire stations are at the scene.
A man in his 50s has been taken to hospital suffering from smoke inhalation and burns, the London Fire Brigade (LFB) tweeted. Emergency crews were called at 1pm and the cause of the blaze is currently unknown.
Kim Ottaway, a barmaid at the nearby Marksman pub told the Evening Standard: "The smoke was so thick you couldn't see outside the window. It was so unbelievably thick.
Monday mayhem. #hackney road #fire #news #London pic.twitter.com/BFtneeX751
— Michelle Goldfarb (@missgoldfarb) June 15, 2015
"It was terrifying... It was terrible the flames were huge, huge, when the roof came down there was a hell of a noise I ran in, I was terrified. We were all outside watching it."
LFB Station Manager Keith Cunnew who is at the scene said: “A member of the public spotted smoke and called the Brigade. On arrival crews wearing breathing apparatus helped three women and three men leave the properties either side of the fire and two other people left the property before the Brigade arrived.
“We expect to be on scene for a number of hours. We are making good progress, but it will take some time to damp down the fire.”
Road diversions are in place and are expected to last into the evening, Hackney Borough Police. Haggerston Park, Hackney City Farm and Haggerston School may be affected by the road closures.
We're making good progress tackling the fire at Yorkton St in #Hackney pic.twitter.com/GmnyRRo9Tm
— London Fire Brigade (@LondonFire) June 15, 2015
Crews working hard fighting the fire on Yorkton St in #Hackney range of shops and roof alight pic.twitter.com/5JVhfinWsO
— London Fire Brigade (@LondonFire) June 15, 2015
Lunchtime drama in East London! Amazing work from @LondonFire pic.twitter.com/u0vPEH2bND
— Paul Jacob (@pauljacob74) June 15, 2015
Part of roof is alight at the fire on Yorkton St in #Hackney, 72 firefighters at the scene. pic.twitter.com/GZ28tNjoOw
— London Fire Brigade (@LondonFire) June 15, 2015