Twelve fire engines and around 80 firefighters have been called to a fire at a leisure centre in Highbury Crescent in Highbury.
Part of the roof of the single-storey building is alight.
Station Manager James Chapman, who is at the scene, said: “Crews are working very hard in difficult conditions to bring this large fire under control.
“A number of local road closures are in place around the site, so motorists are advised to avoid the area if possible.”
Around 100 members of the public and staff left the building before the Brigade arrived. At this stage, there are no reports of any injuries.
The Brigade was called at 1203. Fire crews from Islington, Holloway, Stoke Newington, Paddington and surrounding fire stations are at the scene.
The cause of the fire is not known at this stage.
We’re working on bringing you the latest updates on this breaking news story. Breaking news is updated regularly, please refresh this page or check back later for updates. Don’t forget to follow us on Facebook:@uknip247 and Twitter:@uknip247.