The United Nations has warned that more than 12 million children in the Middle East region remain out of school mostly due to poverty, discrimination and violence.

The United Nations children’s agency, UNICEF, said Wednesday that despite efforts by Middle Eastern countries to expand education, the crisis of children out of school persists.

The UNICEF added in its report that the ongoing conflicts in Iraq and Syria have forced three million children out of school.

The dropout rate in the region had been declining, “often by as much as half,” the UNICEF said, but the new wave of violence and bloodshed in those countries has caused the progress to stall.

The U.N. indicated that of those children out of school, 4.3 million are primary-aged children and 2.9 million are lower secondary-aged children, while 5.1 million children are deprived of pre-primary school education. The total, about 12.3 million, roughly represents 15 percent of the entire child population in the Middle East.

The report states that Yemen is one of the countries hit worst, with only 6 percent of children receiving pre-primary education, while the ongoing military aggression by Saudi Arabia on Yemen has displaced hundreds of thousands of people which could further increase the number of dropouts in the Arab nation, the UNICEF said.

Yemen had the worst rate of pre-primary school age children receiving an education, with only 6 percent of them in school. However, Djibouti and Sudan had the worst rates for secondary school-aged children, followed by Iran and Morocco, according to the report.

The study covered nine countries in the region, revealing the wide range of reasons why children are out of school.

In a lot of the cases, families could not afford the costs associated with schooling, including books and uniforms, while they also weigh the losses of income from a child who could be put to work.

“Children from poor, disadvantaged families are most likely to be excluded from schooling, even though they have the most to gain,” said Maria Calivis, UNICEF’s regional director.

Another issue is gender discrimination, as “girls are undervalued and, since they are not expected to work, their families see no need for them to learn,” the report indicated, while adding that early marriage is also an issue in most countries in the region.

“It’s the poor, rural girls who are the most disadvantaged,” said UNICEF official Dina Craissati.

The UNICEF urged Middle East governments to increase their budgets for education, while recognizing that widespread violence in Syria and Iraq, and the developing conflicts in Yemen and Libya, would present serious challenges to improving education in these countries.