Rates of unauthorised absence among school children in Northern Ireland are double that in England, a Stormont committee has found.
The Public Accounts Committee (PAC) expressed concern the percentage of absence that was not approved rose from 27% to 33% in the four years up to 2012.
Committee members highlighted particular concerns about attendance levels among pupils from socially deprived backgrounds, Traveller children and those in care.
They accused the specialist support body, Education Welfare Service (EWS), of not being on top of the problem of non-attendance.
The EWS is provided by the Education and Library Boards and it employs 134 Education Welfare Officers at a cost of £8.8 million each year.
The committee found that 16,000 cases of pupils being off for more than six weeks in the year had not been referred to the EWS.
Committee chair Michaela Boyle said: “Education is crucial for our young people and we are very concerned that they are not taking advantage of their opportunities.
“We know that there are complex reasons why a child might be absent from school and it is important that the education system gets to grips with tackling these issues. This is the only way that the system will manage to break the vicious cycle of underachievement of the most vulnerable groups of our society.”
The report found that many of those who miss school are not contacted by the EWS and therefore do not get the help or assistance they might need.
The committee recommended that the EWS put into place a mechanism to identify pupils requiring help at the earliest possible opportunity.
“The committee accepts that there is no simple solution to resolving these issues,” said Ms Boyle.
“However, our report found that there were examples of schools that have managed to deal with the issue of non-attendance through collaboration with parents and communities, despite very challenging circumstances.
“We believe that more can be done through better collaboration and the development of a coherent attendance strategy. These mechanisms should be put into place urgently.”