Stillness Primary School is located at Brockley Rise, SE23. We'll bring you more details as soon as possible.
UPDATED: Courtesy of a reader post, here is video footage of the fire.
UPDATED: The school has issued the following statement:
You may have heard or seen that there has been a fire at Stillness Junior School this afternoon. Unfortunately, the Annexe Building to the front left of the school has been severely damaged and cannot be used. However, at present, we are anticipating that school will start as planned on Monday, 6th September, although there will be adjustments to the classrooms.
UPDATED: Bert has posted these photos of the fire being tackled.