The Louisiana Department of Health closed an oyster harvesting area after 15 people reported norovirus-like illnesses.

The department said the Louisiana Oyster Task Force and local harvesters were notified of the closure on Tuesday, and that it’s working with the Department of Wildlife and Fisheries to ensure no oysters are harvested from the area for at least 21 days. Oysters from other parts of Louisiana are safe to eat, the department said.

The outbreak was reported late last month in southwest Alabama and left 11 people ill, including three who sought emergency room treatment.