A total of 28 cases of hepatitis A infection have been reported over the last few months in Norway, where this disease is said to be rare, local health officials said.

Health authorities, who were worried by the growing number of hepatitis A cases, are working to determine whether the sick people are infected from a common source.

In almost half of the cases, the patients were found to have infected with hepatitis A virus while traveling abroad,

The remaining half got infected in Norway, which was described as a rare occurrence.

Infection of hepatitis A virus can also occur through person to person contact.

Symptoms of hepatitis include fever, nausea, vomiting, abdominal pain and jaundice.