Magnetic balls sold exclusively at Walmart have been recalled after similar products were linked to seven deaths, the U.S. Consumer Product Safety Commission announced.

The recall covers the Relax 5mm Science Kit with Large Hematite Magnetic Stone Building Blocks. The 5mm ball sets contain magnets that are stronger and smaller than permitted, CPSC said. If the high-powered magnets are swallowed, they can attract to each other or another metal object and become lodged in the digestive system, resulting in perforations or twisting and blocking of the intestines, infections, blood poisoning or death.

CPSC said there have been no reported incidents related to the kits but some 2,400 magnetic ingestions were treated in U.S. hospitals from 2017-2021 with seven deaths, including two outside the U.S.

The kits were sold on Walmart.com from February 2022 through April 2023 in a set of 216 multi-colored balls encased in a clear plastic case with a portable tin box and black storage bag. The kits cost between $14 and $15.

People are advised to stop using the products and contact maker Joybuy to get a pre-paid label to return them for a full refund. You can contact Joybuy Marketplace Express collect at 302-426-4543 from 9 a.m. to 5 p.m. PT, Monday through Friday, by email at [email protected], or online at https://www.walmart.com/seller/16214 for more information.