MEXICO CITY (AP) - The U.S. has cleared tomatoes in 28 of 31 Mexican states from suspicion in a recent salmonella outbreak.

The U.S. Food and Drug Administration now appears to be narrowing its investigation into the outbreak to some counties in Florida and three Mexican states.

Mexico's Agriculture Department says the decision represents "important progress" and was the result of "a day of intense negotiations between (Mexican) federal authorities and the FDA."

FDA investigators have been tracking where those stricken with salmonella said they bought or ate tomatoes, and where the retailers or restaurants in turn bought them.

They have zeroed in on a list of farms in Florida and Mexico that seem to have contributed at least partly to the supply, plus records showing the packing houses and other distribution stops between the farms and markets.

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On the web:
http://www.fda.gov/oc/opacom/hottopics/tomatoes.html#update

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