A large trove of captured Islamic State records and computer files has provided new details of the extremist group's efforts to send terrorists into Europe, according to senior U.S. intelligence officials.
The material — an estimated 10,000 documents and several terabytes of data — was recovered in recent weeks by Arab and Kurdish forces fighting to retake Manbij, a strategic border town that Islamic State uses to move fighters and supplies in and out of Syria.
The Pentagon trumpeted the intelligence haul as a positive development after a deadly series of terrorist attacks in France and Germany this month raised fears and rattled nerves around the globe.
It also comes after the government in Turkey jailed dozens of military officers, including some who had worked closely with the U.S. in the war against Islamic State, for their alleged role in a failed coup.
Gen. Joseph Votel, who heads U.S. Central Command, which oversees operations in the Middle East, said Thursday that the intelligence haul was "extraordinarily important."
U.S. officials have gained "better understanding of how [Islamic State militants] orchestrate things like foreign fighters, how they are communicating among themselves, how they are managing their resources," he said at a security forum in Aspen, Colo.
Votel said the material includes digital files and communications, paper documents, videos, photos and personnel files of individual fighters.
The initial analysis has provided insights into the location of some Islamic State leaders, the group's network of operatives overseas, and its finances, officials said.
Col. Christopher Garver, spokesman for the U.S.-led coalition in Baghdad, told reporters by teleconference Wednesday that the documents also offer a glimpse into how the militants organize new recruits.
"They would screen them, figure out what languages they speak, assign them a job and send them down into wherever they were going to go, be it into Syria or Iraq," he said.
He said the haul included textbooks used to propagate Islamic State ideology within the group's self-declared caliphate.
"These are textbooks on how to control the lives of everybody that's inside it, how everyone should live their lives, and how if you don't live your life that way, you're an enemy of the so-called, self-proclaimed state," Garver said.
The U.S.-backed Syrian Democratic Forces, made up of mostly Kurdish fighters, have reached the outskirts of Manbij but now face dug-in Islamic State fighters.
U.S. officials believe the Islamic State terrorists who carried out recent deadly attacks in Paris and Brussels moved through Manbij on their way to Europe.
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