Part of a school in Co Dublin has been closed due to structural flaws.
Ardgillan Community College in Balbriggan has 910 pupils.
A structural engineer examined the property on Friday.
A statement from Dublin and Dun Laoghaire Education and Training Board (DDLETB) said: "Opening up (examination of the building behind plaster work) in two classrooms took place on Friday and a consultant engineer on behalf of DDLETB discovered significant structural issues.
"More opening up will be required as a follow up.
"Having considered the engineer's advice and in the interests of the health and safety of the students and staff of the school, DDLETB, in consultation with the Department of Education and Skills and school management, has made the decision to close phase 1 of the school building, effective immediately."
School management is making immediate arrangements to accommodate up to 200 students who will be affected and the school will communicate the details to parents once finalised.
The statement added: "Staff and parents have been informed by the school management and will be kept updated in this regard.
"DDLETB and the school management have emphasised that their absolute priority at all times is the health and safety of students and staff and the above measure is therefore considered appropriate."