A botched U.S. military operation in Niger last fall that left four soldiers dead was reportedly not approved by senior military officials, according to preliminary findings cited by The New York Times on Monday. A report from a Defense Department investigation into the Oct. 4 operation is said to reveal the raid was not approved by top officers, but instead ordered by a junior officer on the ground—the latest finding to raise red flags about the ill-fated mission. Four U.S. soldiers—Staff Sgt. Bryan Black, 35; Staff Sgt. Jeremiah Johnson, 39; Sgt. La David Johnson, 25; and Staff Sgt. Dustin Wright, 29—were killed after being ambushed by militants. Senior military officials were reportedly only aware of the men embarking on a daylong reconnaissance mission, but at some point a junior officer gave the unit an order to target an ISIS-linked militant. The leader of the unit had initially objected, citing insufficient intelligence and equipment, but he ultimately obeyed the orders, according to the report.