The U.S. Consumer Product Safety Commission is warning about the danger of high-powered, pea-sized magnets found in toys, announcing one company’s recall of a set containing them and saying it was aware of seven deaths linked to their ingestion.

The federal agency estimated that ingestion of the magnets led to 2,400 hospital emergency room visits from 2017-2021 in addition to the deaths, two of which it said occurred outside the United States.

“Consumers should stop using the recalled magnetic balls immediately, (and) take them away from children,” the commission said in an online notice. Made from rare-earth metals, each ball measures five millimeters.

The safety commission said the magnets were stronger than permitted by federal toy regulations and could kill children if two or more are swallowed as they can attract each other in the stomach, perforating intestinal walls, twisting and/or blocking intestines — which could lead to infection and blood poisoning.

The Neodymium Magnetic Balls recalled on Thursday were sold by XpressGoods, a North Carolina company, from July 2021 through May 2022 and made in China, the agency said. It said the company offered full refunds and directly contacted purchasers of the roughly 700 units it had sold.

A commission spokeswoman told The New York Times that five other companies that also sold the magnetic balls had refused to do recalls, so it was alerting consumers.

The commission did not say who manufactures the balls.

XpressGoods did not immediately respond to an email seeking comment Saturday.