A big security operation is under way at schools in north Belfast to make sure teachers and pupils are able to get home safely.
They are worried that some of them may be in danger after a Protestant group threatened to kill Catholic workers - including teachers.
The group, called the Ulster Defence Association, say they killed a Catholic postman at the weekend. Two men are being questioned by police about the shooting.
But the big police presence didn't stop one school being evacuated on Monday following a bomb scare.