Days after the FDA issued a do-not-eat warning about imported shrimp sold at Walmart, a Florida company actually issued a recall of that shrimp and a California company recalled shrimp sold under five other brands.

Southwind Foods said it is "voluntarily recalling a limited quantity of frozen shrimp" due to the possible contamination with Cesium-137, a radioactive isotope.

More packages of frozen shrimp potentially affected by radioactive contamination have been recalled, federal officials said Thursday.