Thousands of classroom assistants were picketing Ulster schools today as they began a series of walkouts.
Last-ditch talks between the unions and Education and Library Boards failed to find a resolution last night, and while the majority of special schools were refusing to officially close their doors today, without qualified staff they could not meet health and safety requirements so parents were advised to keep their children at home.
Pupils at mainstream schools requiring assistance were also being advised to remain at home, while a number of mainstream schools were planning to close at lunchtime.
Today's strike is the latest twist in the longest running pay dispute ever seen in Ulster, although the Minister of Education, Caitriona Ruane, this morning said she felt confident the current deadlock can be broken.
"I am pleased that progress has been made towards resolving this dispute and recognising the invaluable work that classroom assistants perform for our children," she said.
"This is a time for moving forward and I am convinced this dispute can be resolved through dialogue that explores new and creative thinking. Further meetings are planned for coming days and by sticking at this we can achieve a positive outcome."
Up to 7,000 school staff remain caught up in a 12-year battle over pay for classroom assistants across the province. They claim they are owed millions of pounds in total salary back payments and have been waiting more than a decade for a job evaluation exercise to be completed.
There are concerns that an increased working week will lead to even lower wages for classroom assistants, although the Department of Education has denied that any classroom assistant will lose out in the job evaluation scheme which is being negotiated.
However, union representatives argued they had been forced to take industrial action to protect classroom assistants being employed in the future, as well as the level of education being delivered to children in schools across Northern Ireland.
General Secretary of Nipsa, John Corey, said: "The facts are over 93% of our classroom assistant members voted for strike action.
"That unprecedented vote reflects the anger and frustration of classroom assistants. They are entirely justified in taking this action. Talks alone will not solve this dispute."
Thousands of Nipsa members were also expected to gather at Custom House Square in Belfast today to take part in a rally to demonstrate solidarity.
If no resolution is found, Nipsa plans to continue strike action with a three day walkout next week and all-out strike action due to begin on October 8.
Meanwhile, Ulster schools could be hit with more walkouts as cleaners and classroom assistants who are members of the public service union are currently voting on whether they should take industrial action.