OMAHA, Neb. -- Nebraska Beef Ltd. is recalling nearly 532,000 pounds of ground beef produced in the last two months because the meat has been linked to an outbreak of E. coli illnesses.

The federal government said late Monday that some of the Omaha-based company's beef was sold by grocer Kroger Co., and investigators traced the meat to Nebraska Beef after 35 people in Ohio and Michigan became ill.

Kroger already recalled beef it sold in those states.

The boxes bear the case code “10260,” and were produced on May 19. These products were distributed to wholesalers in Illinois, Michigan, New York and Pennsylvania.

Much of the beef that Nebraska Beef is recalling was sold to wholesalers or other processing companies, so it may be difficult for consumers to determine if they have any of the beef.

Details about the recalls are available at the USDA Web site.