The U.S. Food and Drug Administration launched an investigation last week into the source of non-viral hepatitis cases that may be linked to a popular brand of alkaline water.

On March 13, the FDA was alerted to five cases of acute non-viral hepatitis (resulting in acute liver failure) in infants and young children that occurred in November with an unknown cause, which was reported by the Southern Nevada Health District. The five children were hospitalized and have since recovered.

The children had all consumed “Real Water” brand alkaline water, so the health agency has advised the restaurants, retailers and consumers to cease selling and consuming the product until its investigation is complete, according to a news release.

“We are advising consumers, restaurants and retailers to not consume, cook with, sell or serve “Real Water” alkaline water until more information is known about the cause of the illnesses,” Frank Yiannas, the FDA’s deputy commissioner for food policy and response, said in a statement. “We are working to determine how the alkaline water may be related to the illnesses. Although the investigation is ongoing, epidemiologic information currently indicates that this alkaline water product may be the cause of the illnesses. We will provide additional updates as more information becomes available.”

The consumption of “Real Water” brand alkaline water is the only common link identified between all of these cases to date. This brand of alkaline water is owned by Real Water Inc., headquartered in Mesa, Arizona. The company also has a headquarters in Nashville, Tennessee.

The patients who were hospitalized live in four different households. Additional people in the households were reported to have experienced less severe symptoms, according to the report. Less severe symptoms included fever, vomiting, nausea, loss of appetite and fatigue.

Symptoms of all types of hepatitis, including non-viral hepatitis, are similar and can include fever, fatigue, loss of appetite, nausea, vomiting, abdominal pain, dark urine, clay or gray-colored bowel movements, joint pain, yellow eyes and jaundice. Those experiencing these symptoms should contact their doctor.

“The FDA is committed to protecting the health of Americans and is especially concerned when there is a food safety issue impacting our youngest, and some of the most vulnerable in the population – infants and young children,” Yiannas said. “We are working closely with the CDC, state and local partners to complete our investigation and monitor for any additional illnesses.”