Hundreds of people have been evacuated from a gym in East London following a "chemical incident".
The drama unfolded shortly after 9am, with crews discovering "elevated" levels of fumes in the building.
In a brief statement London Fire Brigade said a "mix of chemicals" had caused "high levels of fumes and vapour" in the building.
It is unclear if anyone was injured in the incident, but the brigade said people have been evacuated as a precaution.
It posted on Twitter: "Firefighters have been called to a chemical incident at a health club in Canary Wharf.
Have you been affected by this incident? Email webnews@mirror.co.uk
"Around 900 people have been evacuated as a precaution. Crews remain on scene."
Firefighters have been seen using breathing equipment to enter the building.
It is unclear at the moment what chemicals caused the incident.
Station Commander Dave Hill, who is at the scene, said: “Crews have carried out a sweep of the building and found elevated readings.
"Firefighters have ventilated the building and are monitoring the levels of fumes.
“We have evacuated around 900 people from the building as a precaution."
Five fire engines were at the scene, as well as an ambulance, while parts of West India Avenue, Cabot Square and North Colonnade have been cordoned off to traffic, MyLondon reports.
Pictures show at least 12 firefighters at the scene.