WASHINGTON — Strange reports of up to 10 B-2 stealth bombers flying above Minneapolis started circulating on social media Thursday evening.

Tail spotters posted numerous photos on Facebook, not only of B-2s but of KC-10 tankers in the area. Meanwhile, aviation geeks on Twitter began debating what could have prompted perhaps half the inventory of the U.S. Air Force’s most advanced bomber to begin coalescing around a major U.S. city.

Was it an exercise, or something more sinister? Were the B-2s moving in preparation of further airstrikes on Syria? Were they about to send a message to Iran? Was a nuclear strike of some sort imminent?

On Friday afternoon, the Air Force finally released an answer.

“Our bombers routinely participate in scheduled air training exercises designed to enhance interoperability,” Carla Pampe, a spokeswoman for Air Force Global Strike Command, wrote in the statement. “These training opportunities develop and improve ready air forces.”

Maj. Christina Sukach, a spokeswoman for Nellis Air Force Base, offered a bit more information about the exercise.

“Neptune Falcon/Neptune Hawk are joint air interoperability exercises designed to maintain readiness and evaluate employment capabilities in a realistic training environment. The exercises, held 16 April to 5 May 2018, consist of U.S. personnel from across the services,” she stated.

Air Force officials declined to comment on how many bombers were involved, whether the tankers were also participating in the exercise or why they were flying over Minneapolis ― perhaps the result of the recent Air Force decision to cut down on public release of information about exercises.

For all we know, maybe the B-2 pilots were Prince fans and were doing some synchronized flying to “The Beautiful Ones.” But the lack of information from the service did nothing to stop speculation and sleuthing from the aviation community, who stumbled across an answer last night before the Air Force released its own statements.

Ankit Panda, a senior editor with The Diplomat, tweeted a commander’s message from April 2017 about Neptune Falcon. In it, from Brig. Gen. Paul W. Tibbets, of Whiteman Air Force Base’s 509th Bomb Wing, described how 10 B-2s — half of the Air Force’s 20 aircraft B-2 inventory — flew in the exercise last year.

“During these 10 sorties, which average over 16 hours in duration, our aircraft operate over the Nevada Test and Training Range with additional forces to conduct a joint interoperability exercise,” Tibbets wrote on April 21, 2017. “Most of our jets will refuel in the air twice to increase duration and to train with our tanker partners to support large force B-2 operations.”

Pentagon reporter Aaron Mehta contributed to this story.