Consumers should avoid all fresh spinach, regardless of whether it is pre-packaged, a chief U.S. food safety official warned on Saturday, saying the number of E. coli illnesses had passed 100.

Reuters reports that while the FDA did not expand the warning beyond fresh spinach, the investigation into the cause of the illnesses was continuing and other possible sources had not been excluded.

Investigators believe that the spinach was contaminated before it was bagged since more than one bag contained contaminated product, said Dr. David Acheson, the U.S. Food and Drug Administration’s director of food safety and security.

Since August 2, one person has died and 102 people have fallen ill, including 16 who suffered kidney failure after eating spinach suspected of being contaminated with the E. coli 0157:H7 — a potentially deadly bacterium that causes bloody diarrhea and dehydration.

On Friday, Natural Selection Foods LLC/Earthbound Farm, the nation’s largest grower of organic produce, voluntarily recalled fresh spinach products sold in the United States, Mexico and Canada after the U.S. government said they could be linked to the worsening outbreak.