A cigarette which was "carelessly disposed" of was the cause of a fire on the 13th floor of a 20-storey block in Lewisham last week.

Around 150 people were evacuated from flats in Elmira Street on Thursday (June 14), shortly after 4am.

A spokesman for the London Fire Brigade said: “The fire is believed to be accidental and due to the careless disposal of smoking materials.”

Some residents expressed concerns on social media to ask why fire alarms did not sound.

However, the fire brigade says the block was not fitted with fire alarms because adequate safety measures were already in place.

The spokesman said: “If purpose-built blocks of flats or maisonettes are built and maintained correctly they are designed to give you protection from fire.

“This means that walls, floors and doors can hold back flames and smoke for 30 to 60 minutes.

“High-rise residential buildings are not typically fitted with communal fire alarms as you are usually safer staying in your own flat unless heat or smoke is affecting you.

“If you leave your flat you could be rushing into dangerous smoke, the fire itself or firefighters using equipment to bring the fire under control in another part of the building.”

Nobody was injured in the fire and a spokesman for the operator of the building, Barratt Homes, said it was dealt with “safely and quickly”.

The spokesman added: “Heat and smoke detectors and sprinklers are present in all apartments. Full fire safety procedures in the building were followed successfully and we would like to thank the London Fire Brigade who responded swiftly.

“All residents have now returned to the building and we are conducting an investigation.”