OAK BROOK, Ill. (AP) — McDonald's Corp. says it will begin serving sliced tomatoes again after a multistate salmonella outbreak caused the world's largest restaurant chain to yank the fruit from its sandwiches.

Spokeswoman Danya Proud said Saturday that the fast-food chain's U.S. restaurants will reintroduce sliced tomatoes in the next seven to 10 days.

McDonald's was among several restaurant chains and grocery stores that stopped serving sliced tomatoes last Monday as a precaution.

At least 228 illnesses in 23 states were linked to salmonella-tainted tomatoes.

Federal authorities haven't pinpointed the source of the outbreak, but they say parts of Florida and Mexico were supplying most of the nation's tomatoes when the outbreak began in April.