Two women have been arrested on suspicion of producing drugs as 10 people were taken to hospital after being exposed to an unknown chemical substance.
Police were called to a block of flats in Landridge Road, Fulham, at around 12.44am on Wednesday following reports of a fire.
Ten people were treated at the scene, mostly for respiratory problems, after being exposed to the unknown substance.
They were taken to hospital and none of them had life-threatening injuries.
Five firefighters were treated by London Ambulance Service crews after the incident.
A police investigation is ongoing to establish the cause of the fire.
The Metropolitan police said that a 43-year-old woman and an 18-year-old woman were arrested on suspicion of conspiracy to supply controlled drugs and conspiracy to produce controlled drugs, as part of its investigation.
The pair were taken to a west London police station before they were bailed pending further enquiries.
Eight fire engines and around 60 firefighters were called to the scene at the west London property.
Crews wearing breathing apparatus helped residents in the block to evacuate their properties, the LFB said in a statement.
A London Ambulance Service spokesperson added: “We were called at 12.39am to reports of a chemical incident in Landridge Road, Fulham.
“We sent a number of resources including ambulance crews, incident response officers, members of our Hazardous Area Response Team and a trauma team in a car from London’s Air Ambulance.
“We responded alongside colleagues from London Fire Brigade.
“We treated 10 patients – mostly for respiratory problems – and took them all to hospital.”
A number of roads were closed as a safety precaution but they have since been opened.
