An outbreak of listeria that contributed to the deaths of three people has been traced to a second production facility operated by Blue Bell Ice Cream.

Blue Bell spokesman Gene Grabowski said Tuesday that a contaminated 3-ounce cup of ice cream was traced to a plant in Broken Arrow, Oklahoma. Ten products recalled earlier this month by the company were traced to a production line at a plant in Brenham, Texas, where the company is based.

The recall began when five patients at Via Christi St. Francis hospital in Wichita, Kansas, became ill with listeria while hospitalized. Officials determined at least four drank milkshakes that contained Blue Bell ice cream. Three of the patients later died.

The contaminated 3-ounce cup was found at the hospital.

The U.S. Centers for Disease Control reports that all five people were hospitalized at the same hospital for unrelated problems before developing invasive listeriosis—a finding that strongly suggests their infections were acquired in the hospital.

Three deaths were reported among these five patients.

Of the four ill people for whom information is available on the foods eaten in the month before Listeria infection, all four consumed milkshakes made with a single-serving Blue Bell brand ice cream product called “Scoops” while they were in the hospital.

The Kansas Department of Agriculture’s (KDA) laboratory isolated Listeria monocytogenes from a previously unopened, single-serving Blue Bell brand 3 oz. institutional/food service chocolate ice cream cup obtained in March 2015 from the hospital associated with this outbreak.

On March 23, 2015, Blue Bell Ice Cream of Brenham, Texas, announced a recall of 3 oz. institutional/food service ice cream cups (with tab lids) of the following flavors: chocolate, strawberry, and vanilla.

CDC recommends that consumers do not eat recalled products and that institutions and retailers do not sell or serve them.

Investigation into whether other products were produced on the same line as the 3 oz. institutional/food service ice cream cups is ongoing, and new information will be provided as it becomes available.

Listeria monocytogenes was previously isolated from the following Blue Bell brand ice cream products collected from Blue Bell Creameries facilities in Texas, South Carolina, or both in 2015: ice cream Scoops, Chocolate Chip Country Cookie Sandwiches, and Great Divide Bars.

Whole genome sequences of Listeria monocytogenes strains isolated from these ice cream products were highly related to sequences of Listeria strains isolated from four patients in this outbreak.

Blue Bell Creameries reported that these products were removed from the market in March 2015. However, contaminated ice cream products may still be in the freezers of consumers, institutions, and retailers.