The Education Minister says children who don't wear face masks to school will be sent home.
From today, students in third class and above will have to wear masks in school.
Only students who have a medically certified exemption will be allowed attend without a face covering.
It comes as Covid cases among 5 to 12 year olds have increased by 47 per cent in the space of two weeks.
Minister Norma Foley says it's an expert-recommended safety measure.