A balcony in east London was destroyed after cardboard boxes stored on it spontaneously caught fire.
Firefighters were called to an address in Connaught Road, Silvertown, shortly after 11am on Saturday, London Fire Brigade said.
Two fire engines and around 10 crew from Stratford and Shadwell fire stations attended the scene.
In an updated statement published on Monday evening, LfB said the balcony, on the second floor of the building, was “destroyed by fire” along with various stored items.
Part of a three-roomed flat on the second floor was also damaged.
There were no reports of any injuries and it took around an hour for the flames to be brought under control.
The statement added investigators believed it was accidental and “caused by sunlight being refracted through the bevelled edge of the balcony glass and igniting cardboard boxes stored on the second-floor balcony”.
An LfB spokesperson said: “On arrival, crews were faced with a well-developed fire on a second-floor balcony.
“The sun is especially strong during these summer months, but fires caused by refracted and reflected sunlight can happen all year round and are actually quite common.
“Our advice is to make sure that you keep mirrors, crystals, glass ornaments and other reflective items out of direct sunlight at all times.”