Two dogs have been killed just hours apart in separate fires involving an e-bike and an e-scooter.
A charging e-scooter burst into flames at a house in West Hampstead at 10.30am on Monday, said London Fire Brigade (LFB).
The blaze quickly spread and around 60 firefighters were sent to the scene to put it out.
No people were hurt but a dog was found dead inside the property.
Early on Tuesday, the battery pack of a converted e-bike ignited inside a house in Feltham at 2.35am.
Four people left the property, two of whom were later taken to hospital.
Firefighters rescued two trapped dogs, but a third dog died in the blaze.
Both homes were gutted in the fires.
LFB recorded 142 e-bike fires and 29 e-scooter fires last year.
Three people have died and more than 100 have been injured in fires caused by e-bike battery failures in London since the start of 2023.
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LFB deputy assistant commissioner for prevention and protection Richard Field said: “It cannot be underestimated the level of destruction each of these fires have caused, with both homes completely damaged by fire and smoke.
“It’s extremely fortunate that no people have been seriously hurt but a dog was sadly found dead at the scene of each fire.
“Both of these fires were caused by catastrophic battery failures.
“When these batteries fail, they can cause ferocious fires, and the consequences can be devastating.”
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Mr Field added: “From our investigations, we know many of the fires we’ve attended have involved second-hand vehicles or a bike that has been modified using parts bought online.
“We understand that people are trying to save money, but if you spot a deal that looks too be good to be true, it probably is.”