Fifteen fire engines and around 100 firefighters were sent out to tackle a huge blaze at a recycling centre in Morden, south London.
London Fire Brigade were scrambled to Amenity Way where they found a pile of rubbish measuring 20 metres by five metres up in flames at 3am on Saturday.
As of 10am, the force said the fire is now under control but that crews will remain on scene damping down hotspots.
Station commander Scott Thorpe said: "Crews worked tirelessly throughout the night in extremely hot conditions.
“This is a protracted incident and crews are expecting to remain on scene for many hours to come.
"It's expected to be a warm day but we're reminding local residents to continue to keep their windows and doors due to the heavy smoke.
“Specialist teams are working to monitor air quality in the area."
Fire crews from New Malden, Mitcham, Sutton, Wimbledon, Wallington, Surbiton, Norbury and surrounding fire stations attended the scene.
The cause of the fire is not known at this stage.