Glengormley High School has had to close due to a problem with the school’s fire alarm system.
A spokesperson for the Ballyclare Road school said: “A technical fault with our fire alarm system is resulting in them constantly ringing.
“A contractor is trying to resolve this, but for safety reasons we cannot permit pupils to remain on site whilst the fault is unresolved.
“This has never happened before today and we are sorry for this inconvenience to all pupils and parents. We apologise for the late notice.”