(Bloomberg) – Consumers should avoid eating products containing peanut butter until authorities find out more about a salmonella outbreak that may have caused the deaths of six people, the US Food and Drug Administration said.

"We urge consumers to postpone eating those products including peanut butter until further information becomes available," Stephen Sundlof, director of the FDA's Center for Food Safety and Applied Nutrition, said today.

The FDA and the Atlanta-based Centers for Disease Control and Prevention are focusing their investigation on a Blakely, Georgia, plant where closely held Peanut Corp. of America makes peanut butter and peanut paste.

Yesterday, US health officials said 453 people had become sick from the food-borne illness and five people may have died because of salmonella.

The outbreak has spread to 43 states and Canada since mid-September.

"The increase in cases that we have seen is a result of the delayed onset," said Robert Tauxe, deputy director of the Division of Food-borne, Bacterial and Mycotic Diseases at the Atlanta-based CDC on a conference call.

Kellogg Co., the largest US cereal maker, has recalled 7.03 million cases of peanut-butter sandwich crackers and cookies that may be tainted with salmonella.

Snack-size packs of Famous Amos and Keebler peanut butter cookies, and Austin and Keebler peanut butter sandwich crackers are being recalled.

The FDA's Sundlof said the agency doesn't have the authority to order a mandatory recall of the products and has to rely on manufacturers to pull the food off retailers' and outlets' shelves.

The American Peanut Council urged consumers to postpone eating products made with peanut butter while further information on products made at the Blakely plant are sought, the Alexandria, Virginia-based council said in a statement.

"While approximately 99.9 percent of peanut butter and peanut paste in America did not come from the Blakely plant, consumers must err on the side of safety," Patrick Archer, the council's president, said in the statement.

King Nut Cos. recalled its King Nut and Parnell's Pride brand peanut butters on Jan. 10 after salmonella was identified in one open five-pound tub.

The Solon, Ohio-based company distributes peanut butter through food-service accounts to schools, hospitals, universities, health-care facilities and restaurants.

H.E. Butt Grocery Co., a retail chain in Texas and northern Mexico, issued a state-wide recall on three of its snack pack products containing peanut butter dip made by Peanut Corp., according to a statement from the San Antonio-based company.

The recall is only a precaution and none of its customers had reported any illness, the statement said.

Salmonella can cause serious and possibly fatal infections in young children, weak or elderly people.

Healthy people may experience fever, diarrhoea, nausea, vomiting and abdominal pain if infected by the bacteria.

Peanut paste is used in a variety of products, including cookies, crackers and ice cream. Kellogg, of Battle Creek, Michigan, put a "precautionary hold" on its Austin and Keebler peanut butter crackers on January 14, pending results of the investigation.

Peanut butter sold in grocery stores doesn't appear to be associated with the outbreak, officials said earlier.

Connecticut is among the states confirming cases of salmonella.

Yesterday, the state's consumer protection department said it had confirmed the presence of the bacteria in a five- pound tub of unopened King Nut peanut butter found at a food distributor.