The U.S. State Department is currently facing pressure to formally recognize the purge of Christians from Iraq and Syria as genocide. The Islamic State added to the mountain of evidence against it by releasing a video that shows hundreds of Christian books burned in the captive city of Mosul.

The UK Daily Mail reports the video is titled “Diwan of Education Destroys Christian Instruction Books in Mosul.”

The title refers to the Diwan al-Hisba, whose title translates to “Chamber of Morality Police.” They are essentially the enforcers of sharia law inside the Islamic State’s conquered territories, imposing “penalties ranging from flogging for minor misdemeanors like smoking to amputations and beheadings.”

The book bonfire in this new ISIS video is not their first assault on “blasphemous” writings. Last February, the Islamic State blew up the major library of Mosul, wiping out over 10,000 books, some of them irreplaceable volumes dating back to the Ottoman Empire. A systematic effort to wipe out other libraries on Mosul has been under way ever since, along with the Islamic State’s efforts to wipe out “pagan” historical sites.

“These books promote infidelity and call for disobeying Allah, so they will be burned,” an ISIS militant explained to Mosul residents at the time.

ARA News reports the jihadis described the Christian works they burned as the “books of infidels,” collecting them from schools and churches across Mosul.

Christians have been forced out of their ancient communities in Iraq and Syria to flee as ISIS took over, so these book burnings represent a mop-up operation to erase all trace of their presence from regional culture.

“I wish I were in my hometown Mosul right now, but we can’t come back to our areas and live with Daesh,” one Iraqi Christian refugee in Germany told ARA News. “It was difficult to stay there as a Christian.”