Sinn Féin has called for the Stormont assembly to be recalled to deal with the rising number of pupils who are missing from school because they have tested positive or been in close contact with someone who has contracted Covid-19.
Some teachers have voiced concern over the number of pupils who are absent less than two weeks into the new school term. In one instance, the principal of Larne High School reported that more than half of the pupils have been told to stay at home.
It comes as the executive is meeting on Monday to discuss further minor relaxations of Covid regulations.
Education Minister Michelle McIlveen said that the current situation in schools is "a challenge".
She told the BBC: "I've spoken to the health minister this morning and I plan to do that again as we go through the day, just to see what we can do in order to try to assist schools.
"Our main focus is about ensuring that our young people remain in education and that we don't have prolonged lengths of time when they are away from school."
Last week, the minister announced that more than £5.5 million was being made available to help schools deal with the situation.
When pupils are off school as a close contact, they have to undergo a Covid test on day two of their absence. If it is negative they are allowed to return to school but have to take another test on the eighth day after contact.
There have also been reports of long queues at some Covid testing centres in Northern Ireland, with some facilities struggling to accommodate the number of students requiring a test to return to school.
Sinn Fein MLA Pat Sheehan said there was a "lack of clear Covid-19 guidance for schools".
He added: "The Education Minister needs to give clear guidance and put in place the necessary resources to support our school staff in keeping schools open.
"I have initiated a recall petition to ensure that the Education Minister comes to the Assembly and sets out exactly what the Department of Education will do to support schools.
"Schools have been clear on the need for department staff to help with contact tracing and better access to the Covid 19 helplines.
"Keeping our schools open and ensuring the safety of pupils and staff must be a priority."
The Executive meeting, which was delayed from last week after deputy First Minister Michelle O'Neill contracted Covid, has been hearing that the number of positive Covid cases in Northern Ireland has begun to decline in the last few days, and that hospital admissions are expected to begin to decline.
Ministers are expected to agree on further relaxation of measures in hospitality venues and domestic settings.
Meanwhile, nine further deaths of patients who had tested positive for Covid-19 have been reported in Northern Ireland.
The Department of Health said there had also been 1,764 new confirmed cases in the last 24-hour reporting period.
On Monday morning, there were 407 Covid-19 inpatients in hospital, 46 of whom were in intensive care.
