Avoid eating shellfish imported from South Korea, advises the Minnesota Department of Agriculture.
The warning comes on the heels of an evaluation by the U.S. Food and Drug Administration that found South Korea's shellfish industry does not have adequate sanitation controls.
Federal investigators say there is a significant risk of contamination from water-borne pathogens such as norovirus, and the FDA has banned imports of fresh and frozen Korean clams, mussels and other shellfish.
No illnesses have been reported recently, but last fall three people in Seattle got sick after eating oysters from Korea.
Minnesota health officials will visit food wholesalers and retailers to make sure there are no at-risk products on the shelves.
The federal import ban does not affect canned shellfish.