The US Food and Drug Administration has  issued a warning to customers to be more vigilant about the packaged food they buy after Whole Foods wrongly labeled chicken salad as vegan.

Whole Foods Inc. early last week mixed up the labels of its curried chicken salad and the vegan version, which uses soy instead of chicken. The mix up was noticed two days later by an employee and the company recalled the products and put up notices informing people of the mix-up

The wrongly labeled products were sold Tuesday and Wednesday.

"Due to the label mix-up, allergens were undeclared," the company said in a statement on the U.S. Food and Drug Administration's recall site. "The vegan chick'n salad contains soy, and the curried chicken salad contains egg."

The main concern regarding the mismatch of the labels was the fact that people allergic to soy, eggs or chicken could have been seriously affected if they had consumed the product. Ideally, when a product is labeled correctly, the allergens are declared. Hence, the US Food and Drug Administration issued a warning asking customers to be aware of the food items they buy and to check its content whenever possible.

The regulatory body noted that no illnesses have been reported yet as a result of the mix-up but posted a list of places where the wrongly labeled food items were sold. The FDA also confirmed that all wrongly labeled products have been removed from the salad bars in all stores.

Libba Letton, a spokeswoman for Whole Foods, said that the products were wrongly labeled by a company-owned commissary that supplies produce to the company. The company also offered a full refund for the wrongly labeled products.