Federal agents searched two Salinas Valley spinach processing plants Wednesday for evidence linked to the nationwide E. Coli outbreak that sickened 192 people.

Agents from the FBI and the Food and Drug Administration's criminal investigations office executed search warrants at the San Juan Bautista plant of Natural Selection Foods LLC and Growers Express in Salinas to determine whether they didn't follow food safety procedures.

"We are investigating allegations that certain spinach growers and distributors may not have taken all necessary or appropriate steps to ensure that their spinach was safe before they were placed into interstate commerce," U.S. Attorney Kevin Ryan said in a statement.