Three children in Indonesia have died from the mysterious liver disease, the country's health ministry said, raising the global death toll to at least four and leaving doctors from the United States to Asia scrambling to find answers.

This severe strain of acute hepatitis has been identified in nearly 230 children in 20 countries, the World Health Organization said, raising concerns 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.

This emergence of a possible new disease afflicting only young children – most are under the age of 10 with no underlying conditions – has sent ripples of concern through a global health community already grappling with COVID-19.

According to the WHO, the majority of the cases have appeared in Europe, particularly in Britain when there was an "unexpected significant increase" in cases among young, previously healthy children.

In the United States, the Centers for Disease Control and Prevention published a study Friday on a cluster in Alabama, where nine children had also tested positive for a common pathogen called adenovirus 41.

The pathogen is known to cause gastroenteritis in children.

More about: WHO