After reports of a rash of self-balancing scooters, or "hoverboards," bursting into flames, U.K. officials announced on Thursday that more than 15,000 of the gadgets have been detained at the border.
London fire officials had already warned people during "Back to the Future Day" to keep an eye on their hoverboards as the two-wheeled motorized boards charged. There have been reports across the U.K. and U.S. of the devices catching fire.
Part of the problem is the number of cheap knockoffs being sold alongside more mainstream brands. The hoverboards, which balance similar to Segway scooters but don't have handlebars, range in cost from $300 to $1,500.
"Our teams at sea ports, postal hubs and airports have seen a significant spike in the number of unsafe 'hoverboards' arriving at national entry points in recent weeks and are working around-the-clock to prevent dangerous items from entering the supply chain," Lord Toby Harris, chair of the U.K. National Trading Standards consumer watchdog agency, said in a statement.
Overall, the agency has examined more than 17,000 hoverboards coming into the country since mid-October, 88 percent of which they deemed unsafe.
The U.K. isn't the only place officials have expressed concern over the gadgets, which became popular after celebrities like Justin Bieber began posting about them on social media. Both Seattle and New York have banned the scooters on city sidewalks.