A south Belfast special school has said its pupils can only attend part-time for two days a week from Monday.
Fleming Fulton became the first special school in Northern Ireland to scale back on attendance, citing the increasing number of Covid cases in the community as the main reason for the decision.
The move goes against the Education Minister's instruction that special schools should remain open to all students.
In a letter to parents, principal Karen Hancock said no additional guidance from the Department of Education had been received by the school since January 5.
"In light of the increasing numbers of positive cases and lack of additional guidance to mitigate risk from Monday 18, January, 2021, I am changing provision to a blend of pupils attending school for two days on either a Monday and Tuesday, or a Thursday and Friday," she said.
"This new arrangement will help ensure that all pupils have equal access to provision. It is currently not possible for teachers to carry out face-to-face teaching as well as provide home learning activities.
"I am very aware of anxiety of both staff and pupils returning to school, including travel on Education Authority (EA) buses and numbers of people in the school building.
"I believe that this will help by reducing the numbers of pupils throughout classes, reduce numbers using EA transport and help ensure consistency and continuity."
Arrangements will be reviewed by governors on Tuesday, February 2.
"If schools receive additional guidance from the minister to mitigate risk, combined with a reduction in Covid-19 cases within our communities, I hope to be able to return to full-time provision as soon as it is safe to do so," she added.
The National Association of Head Teachers said that while special schools staff would work hard to keep them open, there might be circumstances in which a school would be required to reduce hours for pupils.
"That could happen if safe levels of staffing cannot be maintained due to staff illness or absence, vital support from the Education Authority or the Department of Education (DE) is unavailable, or vital and irreplaceable support services and therapies that are needed by children and schools are unavailable," it said.
"We recognise that DE have explained that where onsite provision is not possible for individual young people, remote provision will be made by the school.
"However, we assert that the minister needs to be clear with parents that some factors will inevitably arise to require a reduction in onsite provision in order to keep children safe."
Barbara Spence, chair of the Special Schools Strategic Leadership Group, said she fully understood the reasons behind the Fleming Fulton decision.
"Every child that comes through our doors is a unique child," she said.
"Every school estate is different. Schools have taken decisions, and they haven't taken them lightly. They've taken them for the best, for the needs of the children."