Four schoolchildren have hepatitis A in Swansea
Four children are being treated following an outbreak of hepatitis A in Swansea, say health officials.
Investigations are taking place to find the source of the infection, and close family of the children have been offered a vaccination as a precaution.
Three of the infected children attend the same school.
Hepatitis A causes flu-like symptoms and anyone concerned should contact their GP, said Public Health Wales.
Dr Jorg Hoffmann, consultant in communicable disease control at Public Health Wales, said: "There is no evidence at present that the infection has been transmitted within the school or that there is any wider public risk to the community.
"We are working closely with Swansea council environmental health officers to investigate the cases and to offer advice to parents, school staff and pupils."
He said hepatitis A was a "short-term infection that has very unpleasant symptoms but is rarely serious".
"Symptoms include flu-like symptoms like tiredness, general aches and pains, headaches and fever, as well as loss of appetite, nausea or vomiting, diarrhoea, abdominal pains, jaundice, very dark urine and itchy skin," he said.
"Hands should be thoroughly washed after using the toilet, before eating or preparing food and after cleaning."