Officials are warning people not to eat a number of fresh and frozen ground beef products sold at Canada Safeway and independent grocery stores because they may be contaminated with a potentially deadly strain of E. coli bacteria.

There are five reports of illnesses linked to the products, possibly because of the O157:H7 strain, the Canadian Food Inspection Agency said in a new release on Friday.

The following products are affected by the alert:

• Fresh ground beef (lean, regular, extra lean and market trim) sold at Safeway and some independent grocery stores in British Columbia and Alberta between May 24 and June 5. These products bear "best before" dates from May 25 to June 6 inclusively. Consumers who have purchased fresh ground beef products from independent stores during the time periods described above and are unsure whether they have an affected product are advised to contact the retail store where they were purchased.
  
• Butcher’s Cut frozen ground beef patties in the 1.13-kg size. The affected patties, bearing UPC 58200 21604 and a Julian code date of 143, were sold on and after May 24, 2007, at Safeway stores in Western Canada and in Ontario, west of Thunder Bay.
  
• Sunny Dawn frozen ground beef patties. The affected patties, bearing the Julian date 143-07, were sold on or after May 24, 2007 at some independent grocery stores in Western Canada, the Yukon, the Northwest Territories, and in Ontario west of Thunder Bay.
  

The agency said food contaminated with E. coli may not look or smell spoiled. It warned that consumption of food contaminated with the bacteria may cause death or serious and potentially life-threatening illnesses, such as permanent kidney damage.

Symptoms include severe abdominal pain and bloody diarrhea. Some people may have seizures or strokes and some may need blood transfusions and kidney dialysis.

Calgary-based Canada Safeway is voluntarily recalling the affected products from the marketplace. The Canadian Food Inspection Agency said it's monitoring the effectiveness of the recall.