NEW YORK— Fisher-Price recalled nearly 5 million infant sleepers on Friday, after more than 30 babies died in them over a 10-year period.

The U.S. Consumer Product Safety Commission said anyone who bought a Fisher-Price Rock 'n Play sleeper should stop using it right away and contact Fisher-Price for a refund or voucher. The sleepers, a soft cradle that vibrates, are used to put babies to sleep.

Fisher-Price and the CPSC did not specify how the infants died, but said the deaths occurred after the babies rolled over from their backs to their stomachs or sides while unrestrained. In an article this week, Consumer Reports found that some of the infants died from suffocation.

The voluntary recall comes a week after Fisher-Price and CPSC issued a safety warning on the sleepers. But The American Academy of Pediatrics urged Fisher-Price and the CPSC to recall the sleepers, calling them "deadly."

In a statement Friday, Fisher-Price said that it stood by the safety of its products and said it issued the recall "due to reported incidents in which the product was used contrary to the safety warnings and instructions."

The recall covers about 4.7 million sleepers, which sold for between $40 and $149 since 2009.