WASHINGTON (AP) — Fisher-Price and U.S. product safety regulators are telling parents not to let their infants fall asleep in the company’s rockers after 13 infants died in the devices between 2009 and 2021.

The deaths happened when the babies fell asleep in Fisher Price’s Infant-to-Toddler and Newborn-to-Toddler rockers. The company, along with U.S. Consumer Product Safety Commission, said the rockers should never be used for sleep and infants should never be left unsupervised or unrestrained in them.

Fisher-Price, a division of El Segundo, California-based Mattel Inc., recalled a similar product last year after four infants died after they were placed on their backs unrestrained in the 4-in-1 Rock ’n Glide Soother. Those fatalities, all children under 4 months old, occurred between April 2019 and February 2020.

In 2019, the CPSC recalled another similar Fisher-Price product, the Rock ‘n Play Sleeper, after 30 infant fatalities were reported. Doctors, parents and consumer advocates had warned the company for years that the product was unsafe and should be recalled.

CPSC Commissioner Richard Trumka Jr. said a gag order implemented by Congress in 1981 prevented the agency from issuing an immediate warning to consumers without first seeking permission from the product’s maker. In the most recent case, Trumka said the gag order delayed the warning message by two months.

“Congress must immediately repeal the gag rule,” Trumka said in a release separate from Tuesday’s product warning. “If CPSC cannot issue timely warnings, dangers will remain hidden in people’s homes.”

A new rule finalized by the CPSC requires that infant sleep products have a sleep surface angle of 10 degrees or less. The rule goes into effect on June 23, 2022.

Fisher-Price and the CPSC said the best place for infants to sleep is on their back on a firm, flat surface without blankets or other objects near them.

Fisher-Price has sold more than 17 million Rockers worldwide since the 1990s.

Consumers are encouraged to report incidents involving these or other infant products to the CPSC at saferproducts.gov.