The Health Bureau of the Macao Special Administrative Region confirmed Monday that it had received reports of mass flu symptoms in one class of a primary school, the fourth mass flu report in just four days.

According to the Health Bureau, a total of five students aged six to seven had reported symptoms of cough and fever. All have been taken to hospital but released soon after receiving medical treatment.

There were three more reports of mass flu symptoms in classes or children center in the last three days, a situation that prompted the bureau to announce Macao has entered peak period for seasonal influenza.

The Health Bureau has been collecting sample of viruses from some affected children for analysis. It also asked schools involved to enhance flu-preventive measures and students are not allowed to school if they have flu symptoms.