(NEXSTAR) — More than 400 Family Dollar locations remained closed Sunday as the retailer worked to recover from a rodent infestation discovered at one of its distribution centers.

The Food and Drug Administration said it first sent an inspector to the West Memphis, Arkansas, facility in January following a consumer complaint. The inspection found “live rodents, dead rodents in various states of decay, rodent feces and urine, evidence of gnawing, nesting and rodent odors throughout the facility, dead birds and bird droppings, and products stored in conditions that did not protect against contamination,” the agency said.

After fumigation at the facility, about 1,100 dead rodents were found.

“Additionally, a review of the company’s internal records also indicated the collection of more than 2,300 rodents between Mar. 29 and Sep. 17, 2021, demonstrating a history of infestation,” the FDA said.

Concerns that unsanitary conditions could have contaminated food, cosmetics, medical products, pet food and other products sold at Family Dollar has prompted a massive recall.

It has also led the chain to temporarily shut down 404 stores as the affected products are purged from the shelves. The closed stores are all in Alabama, Arkansas, Louisiana, Missouri, Mississippi and Tennessee. (See the exact list of locations here.)

“Our teams are working hard to reopen these stores as soon as possible,” said Kayleigh Campbell, a spokesperson for Family Dollar’s parent company, Dollar Tree. Campbell did not provide an estimated reopening date.

Once stores reopen, customers who purchased affected products will be able to return them for a refund without a receipt.

“We take situations like this very seriously and are committed to providing safe and quality products to our customers. We have been fully cooperating with all regulatory agencies in the resolution of this matter and are in the process of remediating the issue,” Campbell said.

Customers with questions about the recall and potentially contaminated products can call 844-636-7687, the company said.