All sorts of banned items are discovered in luggage by Transportation Security Administration screeners, but cannonballs stolen from a Civil War-era fort are not an everyday find.

Lead TSA Officer Justin Dupree was examining checked bags earlier this month at Alabama’s Gulf Shores International Airport when he spotted the projectiles on his X-ray machine.

“My first thought was, I couldn’t see a fuse and need to get some help quick,” the TSA officer is quoted as saying in a TSA update. “I couldn’t see the entire item but was scared I might have been holding a live explosive.”

There were five small cannonballs wrapped in paper towels, with the largest being the size of a grapefruit and the smallest only about an inch wide, the agency reported.

“I had never seen anything quite this unique,” Dupree said. “I’ve seen inert grenades and training munitions but never an Indiana Jones-esque stolen artifact-type situation.”