The United Nations Educational, Scientific and Cultural Organization (UNESCO) on Tuesday voiced concern over reports of mass book-burning in Iraq, saying it would be one of the most “devastating” such actions in history if confirmed.

Referring to reports that thousands of books on philosophy, law, science and poetry have been torched in recent weeks, UNESCO Director-General Irina Bokova said it was part of a campaign of “cultural cleansing,” reports AFP.

“If confirmed, this would be one of the most devastating acts of destruction of library collections in human history,” UNESCO said.

“Such destruction is a cruel reminder that the nations of the world must remain united to combat such fanaticism today,” Bokova added.

In terms of historical precedent, during the Holocaust the genocidal Nazi regime infamously held regular burnings of books that were deemed “subversive” to its murderous and racist ideology.

Islamic State (ISIS) terrorists currently hold the city of Mosul, the second-largest city in Iraq, where the book burning may have occurred.

US air strikes against the group have aimed to put pressure on the jihadists. Kurdish peshmerga forces have also launched successful offensives against ISIS-held roads near Mosul.

UNESCO said the “armed extremists in Iraq” were targeting “cultural heritage, cultural and religious minorities, and the documents and written evidence of one of the oldest civilizations in human history.”

Last December UNESCO held a special session to discuss ISIS’s rampant destruction of Jewish historical sites in the regions of Iraq and Syria under its control.

Among the damaged Jewish sites are the shrines of the prophets Daniel and Jonah, the Eliyahu Hanavi (prophet Elijah) shrine and synagogue in Damascus, the tomb of Yehezkel (Ezekiel) the prophet, and the Dura Europos synagogue, one of the oldest known synagogues.