A one-day strike by almost 12,000 education board workers is causing disruption in schools and libraries across Northern Ireland.
Union members are protesting against education cuts
Special schools dependent on classroom assistants and specialised transport are expected to be worst affected.
Nipsa, Unison and T&G union members voted to strike over £30m cutbacks.
The boards have blamed inadequate government funding, but new Education Minister Angela Smith said funding had actually increased by about 9%.
However, Ms Smith said additional costs such as pay rises, had impacted on the budget.
She said she would have to study the figures in detail.
"I need to understand why, when there's a 9% increase in funding, we have the boards saying to me: 'There are serious problems here'," she told BBC Radio Ulster.
"Why are we in that position? Let's get to that move first, and then take a step forward from there.
"I will talk to anybody to try to get to the position where we don't have support staff on strike."
She said the only way to resolve the issue was for people to work together with "cool heads".
Staff who are taking strike action include classroom assistants, catering staff, technicians, caretakers, and bus drivers and escorts.
Ten out of Belfast's 11 special schools will not be open for pupils.
Other mainstream schools, especially in rural areas, have warned that education board buses may not turn up for pupils.
Some schools will not have a canteen service and have told children to bring packed lunches.
A number of primary and nursery schools will not open but most secondary schools have predicted they will open as usual.
Some libraries will also be shut, with one board predicting that half of its branches would not open.