Multiple people are being treated for “breathing difficulties” after a “high quantity of chlorine gas” was released at the London Olympic swimming pool.
London Ambulance Service (LAS) said it was treating “quite a number” of patients at Queen Elizabeth Olympic Park following an incident when pool chemicals were delivered at the Aquatics Centre.
Worried parents told LBC there were school swimming lessons at the centre on Wednesday morning.
Emergency services believe there are no fatalities, LBC understands.
Around 14 ambulances were pictured at the scene, along with two incident support units and the fire brigade
The London Fire Brigade asked that locals close their windows and doors until the issue is resolved. A spokesperson said: “Due to a chemical reaction a high quantity of chlorine gas was released.
“London Ambulance Service are treating a number of patients. Around 200 people were evacuated from the centre.
“While we ventilate the premises we would ask those residents in the immediate vicinity to close doors and windows.”
Station Commander Shaun Coltress confirmed that there was not an explosion at the scene, with people instead alerted by a smell.
The Metropolitan Police said officers were on the scene following the “leak of noxious fumes”.
In a statement, the force said: “Officers were alerted by London Fire Brigade at 09:53hrs on Wednesday, 23 March to a leak of noxious fumes at the Aquatics Centre, Queen Elizabeth Park, E20.
“Officers and London Ambulance Service have also attended the scene.
“A number of people have been evacuated from the premises.”
The Olympic Park initially said on Twitter it involved “the release of a gas” at the centre, causing the area to be evacuated and cordoned off.
They tweeted: “There has been an incident at the London Aquatics Centre this morning involving the release of a gas.
“The area has been cordoned off and evacuated.
“We’re working with emergency services on site. There are a number of casualties with breathing difficulties being treated by London ambulance.”
LAS added on Twitter: “We are responding to an incident at Queen Elizabeth Olympic Park and have a number of resources on scene.
“Please only call 999 for genuine medical emergencies and use 111 online for any other urgent medical needs.”
A witness told LBC that “more ambulances have turned up, and they seem to have moved all non-emergency personnel more away from the area now”.
A spokesperson for GLL said: “At approximately 10am this morning we took the decision to evacuate the London Aquatics Centre.
“This was due to a release of gas that occurred when the facilities management company that operates the plant room took delivery of pool chemicals.
“The emergency services were called and some of our customers have required medical treatment. We are working to support all those affected.”
“We are awaiting guidance on when the Centre will be able to reopen.”
A statement from Mayor of London Sadiq Khan on the incident said: “I remain in close contact with our emergency services who are dealing with a gas-related incident at the London Aquatics Centre this morning.
“A number of people are being treated by London Ambulance Service. Please avoid the area which has been cordoned off and evacuated.”
A witness posted online: “Olympic swimming pool in Queen Elizabeth Park Stratford. Not sure what is going on. Hope everyone is OK.”
Another person posted: “Major incident at London aquatic centre Stratford.”