Eight fire engines and 58 firefighters are currently battling a fire at a tower block in Mile End.
The London Fire Brigade (LFB) say half of a flat on the 12th floor of a tower block is alight in Wellington Way, Mile End.
The Brigade received over 90 calls to the fire and were first called at about 12.30pm. Crews from Bethnal Green, Shadwell, Stratford and Whitechapel are in attendance.
Forty people were forced to flee the tower block as smoke billowed over east London.
At this stage, the LFB say the cause of the fire is unknown.
Muhbeen Hussain wrote online: There is a Tower Block in Mile End, London on fire. Fire fighters are attending to it. Pray that everyone is getting out safe.
Emergency services are attending but the fire seems to be very much ablaze.
Jagmail Singh, 35, of Bow Food & wines, said: Someone came running in the shop saying there was a fire across the road.
I called the fire brigade straight away but they said they’d already received lots of calls on it. The road is still closed off with the police at the moment.
Mr Singh said he was shocked to see it happened so close to his work, and said at one point he could see eight fire engines travelling to the scene.
The fire was under control by 2pm, a LFB spokesman said.
Earlier today London firefighters appeared at the Grenfell Tower fire inquiry to give evidence about the blaze that claimed 72 lives.
David Badillo, part of the North Kensington crew which arrived first at the inferno last June described crying every day after learning of the death of a 12-year-old girl he tried to save.
He recounted the doomed rescue bid in heartbreaking detail as part of a written statement submitted to the Grenfell Tower public inquiry, published on Friday.