E-scooter crashes shot up almost 2,800% in London in the first half of 2021 compared to the entirety of 2018, new figures show.
There were 258 collisions in the capital in the first six months of last year, according to Met Police data.
Across all of 2018, there were just nine. The number rose to 38 the following year, before a spike to 266 in 2020.
Privately-owned e-scooters are a common sight on roads and pavements in UK cities, even though they can only be legally used on private land.
Some 3,637 of the scooters were seized by the Met Police between January and November 2021, and any owners wanting to retrieve them must pay £150 and a £10 daily storage charge.
Last June, London joined dozens of towns and cities across the UK in launching an e-scooter rental scheme under government trials, which began in July 2020.
These involve several safety measures, such as maximum speed limits and automatic lights.
Transport for London (TfL) banned private e-scooters on its network last month after one burst into flames at Parsons Green Tube station.
Figures 'likely just the tip of the iceberg'
The new data was obtained by Labour's London Assembly policing and crime spokesman, Unmesh Desai.
Mr Desai, who got the figures in response to a question to London mayor Sadiq Khan, said: "The use of illegal e-scooters on our roads and pavements is putting Londoners at risk of significant harm, especially the most vulnerable in our communities such as people with limited mobility, visual impairments and hearing loss.
"Whilst it is concerning that these figures are likely to be just the tip of the iceberg, it has been encouraging to see the scale of enforcement action taken by TfL and the Met Police so far.
"My message to Londoners is that the only legal way to use an e-scooter in the capital is through the trial being run by TfL and London councils in certain boroughs."
A 74-year-old was killed on New Year's Day when he crashed his e-scooter into two parked cars in Manchester.