Sen. Amy Klobuchar, D-Minn., is asking federal safety regulators to address what she called an "alarming increase" in injuries from rare-earth magnet ingestion by children, according to a letter the senator sent Friday to the Consumer Product Safety Commission.

The letter from Klobuchar, who is running for the Democratic Party's presidential nomination, is in response to a Washington Post article published Thursday that detailed a surge in magnet ingestions since a federal court struck down a CPSC ban on the products in 2016. That allowed the powerful magnets back on the market.

Nearly 1,600 ingestion cases were expected to be reported to the nation's poison control centers this year. Rare-earth magnets are usually found in popular desk toys made up of hundreds of BB-sized balls. Doctors said the magnets pose an unusual risk because just two magnetic balls can cause permanent internal injuries.

The Post article explained how, with the CPSC sidelined by the courts, magnet companies are using a voluntary safety standards process to largely regulate itself.

"Given the seriousness of this issue, I urge the CPSC to revisit this issue and take action to protect children from the dangers of small rare-earth magnets," Klobuchar wrote in her letter.

The senator also asked the agency to list what it is doing to investigate the number of injuries and whether the agency needed additional resources to protect children from the products.

"We have received the letter and are looking into it," CPSC spokesman Joe Martyak said, "and we will respond to the members of Congress."