Police in Cardiff Bay have seized more than 40 illegal e-bikes and scooters in just one week.
Neighbourhood officers say the MPVs (mechanically propelled vehicles), which had been illegally adapted, will be sent for destruction.
In total, 31 e-bikes and 11 scooters were seized in the Butetown and Grangetown areas.
Sergeant Samantha Johnson from South Wales Police said: "We’re committed to keeping our streets safe. We will not tolerate illegal activity in our communities."
"Unlawful use of e-bikes and e-scooters is not only illegal but also puts pedestrians and road users at serious risk. We urge the public to understand the law and make safe, legal choices."

Last month, a series of joint operations involving South Wales Police, Cardiff Council and immigration officers led to over 135 MPVs being taken off the streets in the Canton and Cathays areas of the city.
On average, the confisfacted bikes were able to reach speeds of between 25 and 70mph - the legal limit is 15.5mph - with one MPV able to reach a top speed of 84mph.
Two men were also arrested for possessing Class A drugs and a pointed blade.
South Wales Police said they had noticed an improvement in compliance with the law for e-bike users, and a significant decrease in those using illegal and modified e-bikes in the area.

Vueling withdraws winter flights to Aicante this winter
Playground in Barry forced to close after fire damages equipment
Campaigners Take Fight for Fairer Pathways in Welsh Women’s Football to Parliament
Vale Councillor Gwyn John Launches His First Novel at Llantwit Major Book Signing
Pink poppy display commences with celebration of life
Former Barry office block converted into new homes for people at risk of homelessness
Welsh Government publishes independent report on Level 4 intervention at Cardiff and Vale UHB
Three CoastSnap stations set to be installed along the Glamorgan Heritage Coast
Daffodil Runner statue installed at Marie Curie Hospice in Penarth
Woman Dies After Incident in Leckwith as Police Investigation Continues
Vale entrepreneur wins national Innovate UK award for sustainable construction technology
Cardiff Airport retains top accessibility rating as regulator reports record demand for assistance
Open Doors event to showcase hidden world of Glamorgan Archives
New details have emerged of a new tree-lined public square that will replace a traffic dominated junction
Dyffryn Gardens’ Edwardian rose garden blooms again after decade-long restoration
Barry’s Own Daniel White to Walk 190 Miles Back to Where His Round Table Story Began
1,300 people attend Flying Start Family Fun Day
Dispersal order put in place to tackle anti-social behaviour
Interim Chief Executive Appointed at Cardiff and Vale University Health Board
Cardiff Theatre Marks 50 Years of Service for Long‑Standing Staff Member