Mystery liver disease kills three more children after "unexpected significant increase" in cases reported

Three children in Indonesia have died from a mysterious liver disease, the country's health ministry said, raising to at least four the global death toll of a fatal ailment puzzling doctors from the U.S. to Asia.

This severe strain of acute hepatitis has been identified in nearly 170 children across 11 countries in recent weeks -- raising concerns from the World Health Organization (WHO) of the disease's "unknown origin."

The symptoms afflicting the children include nausea, vomiting, diarrhea and abdominal pain -- before their livers showed signs of inflammation. At least one death was previously reported by WHO.