WASHINGTON (AP) — Federal health officials are apparently zeroing in on the source of at least some of the cyclospora infections that have sickened more than 400 people in 16 states. The Food and Drug Administration says the outbreak of stomach illnesses in Iowa and Nebraska is linked to salad mix served at Olive Garden and Red Lobster restaurants in those states. The salad mix was supplied by a Mexican farm.

Both Olive Garden and Red Lobster are owned by Orlando-based Darden Restaurants. A Darden spokesman said the FDA’s announcement is “new information” and that there have been no previous problems with the supplier — Taylor Farms de Mexico. It’s the Mexican branch of Taylor Farms of Salinas, Calif.

The FDA says its’ investigation has not implicated any package salad sold in grocery stores. It’s also not clear if there is a connection to illnesses in 14 other states.