Al Qaeda-linked Islamist rebels torched the Ahmed Baba library in Timbuktu as the militants retreated from French troops after holding the city for 10 months. The library, which was built in 2010, holds some 20,000 priceless manuscripts, some dating back to 1204, as the city over the years became the seat of Islamic learning on the caravan trail. Manuscripts were imported to Timbuktu from North Africa and Egypt, and scholars would copy them to add to their own libraries. It's unclear how many of the documents were destroyed. "They torched all the important ancient manuscripts," the mayor, Hallé Ousmane Cissé, told The Associated Press. "The ancient books of geography and science. It is the history of Timbuktu, of its people." But preservationists told Time that although some of them were indeed destroyed, most of the manuscripts are safe due to a rescue operation that hauled out the documents shortly before the militants seized control of Timbuktu early last year. They said staff left behind just a small portion of them, perhaps to conceal the rescue attempt. "They were put in a very safe place," said Mahmoud Zouber, Mali’s presidential aide on Islamic affairs. "I can guarantee you. The manuscripts are in total security."