23 pupils from two classes at Nguyen Hue school, who were suspected of having the disease, were put in quarantine at the centre on August 27 and 28.

The centre has also quarantined some relatives of the pupils, raising the total number being monitored there to 28.

The Vice Headmistress of the school, Hoang Thi Kieu Dung, said the school has allowed the remaining pupils of the two classes to stay away from school for one week and monitor their own health.