Fire crews were called to a chemical leak at a hotel on Knightsbridge this evening.
Around 100 people were evacuated from the basement and first floor of the building and two people were taken to hospital by London Ambulance Service crews.
Firefighters wearing breathing apparatus treated the leak with soda ash, ventilated the area and monitored levels until it was safe to return back inside.
Two fire engines and a range of specialist equipment attended the incident from stations including Chelsea, Kensington and Soho.
The Brigade were called at 1520 and the incident was over for firefighters by 2216.