Nearly 300 probable cases of children with severe hepatitis have been detected in 20 countries worldwide, with some in Southeast Asia, the World Health Organization (WHO) has said, BBC reported.

Health officials around the world are investigating a mysterious increase in cases of liver conditions which was first spotted in the UK.

A common virus called adenovirus, which has rebounded after the pandemic, could be causing the surge, BBC reported. One death has been reported by the WHO.

As of 1 May, it said most cases of young children with hepatitis had been detected in Europe with small numbers also reported in the Americas, western Pacific, and Southeast Asia.

The first cases of this unusual hepatitis were spotted in Scotland in children under the age of 10. More than 110 cases have now been recorded in the UK so far.

Most children had a mild form of liver inflammation, although 10 children have needed a liver transplant, the report said.

They had initial symptoms of vomiting and diarrhea followed by yellowing of the skin or whites of the eyes, called jaundice.

The hepatitis viruses that normally cause the condition (viruses A, B, C, D, and E) were not detected in any of the children.

Countries worldwide started looking for the same unexplained condition 'of unknown origin' in children after it was highlighted by UK health officials.

There is no reason to believe the rare liver condition itself is spreading around the world, BBC reported. (GA/NewsGram)