Cargill has also asked customers to return any remaining patties purchased after Aug. 26 to the store or destroy them.

The children became ill between Sept. 10 and Sept. 20 after eating ground beef patties that were bought frozen under the name American Chef's Selection Angus Beef Patties from three Sam's Club stores in the Twin Cities area.

Sam's Clu voluntarily removed the product from its stores nationwide after the illnesses were reported, the company said.

"We can't be certain that meat from other stores is not involved, since the brand ... was likely sold at other Sam's Club locations," said Heidi Kassenborg, acting director of the dairy and food inspection division of the Minnesota Department of Agriculture.

The patties were produced by Cargill and had an expiration date of Feb. 12, 2008, Sam's Club said in a statement. They were coded UPC 0002874907056 Item #700141.

A Cargill spokesman contacted by The Associated Press said the company would have no comment until Monday.

The Minnesota Department of Agriculture is working with the federal Agriculture Department to determine the source of the contamination.

Two of the children were hospitalized; one remains in the hospital and the other has been discharged, the Health Department said.

Symptoms of E. coli illness include stomach cramps and diarrhea. People typically are ill for two to five days but can develop complications including kidney failure. People who have developed such symptoms should contact their doctor, the Health Department said.

Sam's Club warehouse is owned by Wal-Mart Stores Inc., the world's largest retailer, based in Bentonville, Ark.

Cargill, based in Wayzata, Minn., is one of the nation's largest privately held companies and makes food ingredients, moves commodities around the world and runs financial commodities trading businesses.