The London Fire Brigade said in a statement: “Part of a police station including its mansard roof is alight.
“The fire is producing large amounts of smoke and people in the local area are advised to keep their windows and doors closed.
“Road closures are in place and people are advised to avoid the area while the incident is ongoing.
“Three of the Brigade’s 32-metre turntable ladders and one of the Brigade’s 64-metre turntable ladders are at the scene.
“The Brigade was called at 1617. Firefighters from Stratford, Leytonstone, Plaistow and surrounding fire stations are attending the scene. The cause of the fire is not yet known.”
The Met Police said: “London Fire Brigade are currently dealing with a fire at Forest Gate Police Station on the third floor of the building.
“The building has been evacuated. We are not aware of any injuries or people trapped in the building.
“Road closures are in place at the scene.”