A huge fire has ripped through the roof of a building on Baker Street in central London with 80 fire fighters tackling the blaze.
Twelve fire engines were scrambled to the scene around 6pm and road closures have caused traffic chaos.
Images show huge plumes of smoke coming from a building on the junction of Baker Street and George Street as fire crews attempted to hose it down from a raised platform.
Firefighters were seen using drones to investigate before attempting to extinguish the fire using hosepipes.
People have been told to avoid the area as the building is being dampened down by crews with the fire now under control.
Station Commander Chris Young, who is at the scene, said: ""Crews have been working in challenging conditions but have made good progress extinguishing this fire.
"Although most of the fire is now out, we are likely to remain at the scene for a number of hours damping down and ensuring the scene is safe. We would ask that drivers continue to avoid the area and find alternative routes."
In a latest tweet at 10.15pm London Fire Brigade stated: "Crews have now brought a roof fire in #Marylebone under control. However, we are likely to remain at the scene into the night."
It also said that there have not been any reports of injuries.
Earlier it tweeted: "Twelve fire engines and around 80 firefighters are at the scene of a fire near the junction of Baker Street and George Street in #Marylebone. Roads are closed are people are asked to avoid the area. More info soon."
A statement from the fire service told how the fire service was called shortly after 6pm and that so far the cause of the fire is unknown.
It said: "Twelve fire engines and around 80 firefighters are tackling a fire on George Street in Marylebone.
"A roof of a six-storey building under refurbishment is alight. Two 32 metre turntable ladders are in use and the Brigade's drone team are assisting by providing an aerial view of the incident.
"Road closures are in place by the junction of George Street and Baker Street and people are asked to avoid the area.
"The Brigade was called at 1809. Crews from Euston, Soho, Chelsea, Paddington, Kensington and surrounding fire stations are at the scene.
"The cause of the fire is unknown at this time."
A later update at 8pm by the fire service said that crews were still attempting to contain the fire while again describing it was at a building that was "under refurbishment".