Minnesota health officials are urging parents to watch for signs of liver inflammation in their children, especially those who have had either upper respiratory or stomach-intestinal illnesses.

At least three Minnesota children under age 3 who have had liver inflammation may be part of a national cluster of hepatitis in children. The cause is being investigated, but health officials said it may be associated with infection from a virus know as adenovirus type 41.

The Centers for Disease Control and Prevention announced Friday that at least 109 children in 25 states have been identified as part of the cluster of cases. The World Health Organization has identified 228 cases in 20 countries.

"If your child recently had vomiting and diarrhea or symptoms of a common cold and then develops yellowing of the eyes and skin, it is important to have your child evaluated by a health care provider right away," said Minnesota State Epidemiologist Dr. Ruth Lynfield. "Other symptoms can include abdominal pain, fatigue, dark urine and clay-colored stools. Getting medical care quickly can help diagnose and treat the condition as needed."

Of the Minnesota cases, one child required a liver transplant. The other two children recovered without a transplant, health officials said.

Two other possible cases at Minnesota hospitals involved children who aren't residents of the state.