Mattel Inc. (MAT) voluntarily recalled 4.4 million Polly Pocket Play Sets on Tuesday after three children swallowed tiny magnets from the toys and required surgery.

The announcement was made in conjunction with the U.S. Consumer Product safety commission, which says it had received 170 reports of small magnets coming out of the dolls and accessories in the play sets. Over half of the affected products were sold in department and toy stores in the United States from May 2003 through September 2006.

“When more than one magnet is swallowed, the magnets can attract each other and cause intestinal perforation, infection or blockage, which can be fatal. Aspiration to the lungs requires immediate surgery.”

There were three reports of serious injuries to children who swallowed more than one magnet. All three children involved suffered internal perforations and required surgery. A 2-year-old child was hospitalized for seven days and a 7-year-old child was hospitalized for 12 days. An 8-year-old child was also hospitalized.

Mattel's share price fell 29 cents or 1.26 percent to close at $23.09 in Tuesday trading on the New York Stock Exchange.