WASHINGTON, Dec. 21 (UPI) -- The U.S. Department of Agriculture is warning that fresh ground beef sold at some Safeway stores may have been contaminated with Salmonella.

The beef may have been ground and sold at Safeway supermarkets in Arizona, California, Hawaii, Nevada and New Mexico between Sept. 19 and Nov. 5, 2007, the USDA's Food Safety and Inspection Service said this week in a release.

The public health alert was initiated after investigations by the California Department of Public Health, Arizona Department of Health Services and the Centers for Disease Control and Prevention, determined an association between the fresh ground beef products and 38 illnesses reported in Arizona, California, Idaho and Nevada.

FSIS said it could not identify specific establishments, lots and products that would be subject to a recall. The agency said it has no reason to believe that these products are still available for sale.