drone sighting that temporarily raised alarms at one of the United States Air Force's largest and most strategic airfields earlier this month was more extensive, and potentially more dangerous, than first reported, according to a confidential internal briefing document reviewed by ABC News.

Barksdale Air Force Base in Louisiana said it was under a shelter-in-place order March 9 after "a report of an unmanned aerial system operating over the installation."

The sighting raised concerns because Barksdale houses long-range B-52 bombers and plays a critical role in command and control of the Air Force nuclear defense capabilities.

The shelter-in-place order was lifted later that day but the unauthorized drone flights continued for nearly a week.

"Barksdale Air Force Base detected multiple unauthorized drones operating in our airspace during the week of March 9th," Capt. Hunter Rininger of the 2nd Bomb Wing said in a statement provided to ABC News. The additional drone incursions had not been previously reported.

According to the confidential briefing document dated March 15, the drones came in waves and entered and exited the base in a way that may suggest attempts to "avoid the operator(s) being located." Lights on the drones suggested the operators "may be testing security responses" at the base.

"Between March 9-15, 2026, BAFB Security Forces observed multiple waves of 12-15 drones operating over sensitive areas of the installation, including the flight line, with aircraft displaying non-commercial signal characteristics, long-range control links and resistance to jamming," the document said. "After reaching multiple points across the installation, the drones dispersed across sensitive locations on the base."

According to the document there was no drone activity detected on March 13 and 14 and it's not clear if there has been activity since.

The flights lasted around four hours each day and the drones used varied routes of ingress and deliberate maneuvering within restricted airspace.