A U.N. report says nearly half the schools it runs in the Middle East have been damaged, some severely enough to make them inoperable, in the past half decade, disrupting the education of thousands of Palestinian children, the BBC reported.

The report, by the U.N. Relief and Works Agency for Palestinian refugees, says more than 300 U.N. schools have been attacked or shut down, including more than half of UNWRA schools in Syria. While some of the schools have been destroyed, others, most of which have been looted, are cut off by fighting or are being used as shelters. The report also says 400 teachers have fled Syria.

UNWRA chief Pierre Kraehenbuehl has pleaded with warring factions to spare the schools and the lives of teachers, students and aid workers.

The report, which is to be presented Monday at the World Humanitarian Summit in Istanbul, assesses damage to the schools in Lebanon, Jordan and the Palestinian territories, in addition to Syria. It says the schools are needed to provide stability and hope for the children.

UNWRA says it serves some 500,000 Palestinian refugee children through 692 elementary and prep schools in Gaza, the West Bank, Jordan and Syria, and eight secondary schools in Lebanon, with 51,000 served in Syria alone. At least 302 of the facilities have been affected by conflict in the past five years.

Classes are provided in English, mathematics, Arabic and science. UNRWA says it also offers psychosocial support and teaches survival skills.

The continuing civil war in Syria has seen 4 million people flee that country since 2011, with millions more displaced within its borders, the U.N. Refugee Agency reported this week.

To complicate an already extremely complicated situation, a rift seems to have developed between Free Syrian Army rebels and Kurdish forces in Syria, resulting from a reported incident in which Kurdish fighters are alleged to have killed 50 members of the FSA, and the FSA is reported to have executed two Syrian Kurds in retaliation. The two groups had been fighting the Islamic State group and working together to oust Syrian President Bashar Assad.