A Transportation Security Administration officer discovered five stolen Civil War-era cannonballs concealed in a passenger's checked suitcase during a routine security screening at an Alabama airport on July 18, according to law enforcement officials.

In a statement issued Friday, the TSA said the artifacts were detected at Gulf Shores International Airport after a screening agent spotted a large, opaque object inside the luggage during an X-ray examination. Upon opening the bag, the officer found five small cannonballs wrapped in paper towels and immediately alerted a supervisor.

"I had never seen anything quite this unique," TSA Officer Justin Dupree said in the agency's statement. "I've seen inert grenades and training munitions but never an Indiana Jones-esque stolen artifact-type situation."

The cannonballs — the largest roughly the size of grapefruits and comparable in weight to a shot put — were inactive and contained no explosive material or functioning components, the TSA confirmed. Nevertheless, cannonballs are classified as artillery munitions and are prohibited from being transported on aircraft.

Investigators subsequently determined that the cannonballs had been stolen from Fort Morgan, a historic Gulf Shores fortification that played a notable role in several military conflicts, including the American Civil War. Fort Morgan, designated a National Historic Landmark, is best known for its role in the Battle of Mobile Bay in August 1864, a pivotal Union naval victory. The identification was made based on paint markings that fort staff had previously applied to the artifacts.

The Baldwin County Sheriff's Office announced Thursday that a juvenile had taken the cannonballs from a storage area at the fort and placed them inside their grandmother's checked luggage. The grandmother informed officers that she was unaware the items had been stolen.

Theft of artifacts from historic sites is a persistent challenge for institutions that preserve and display military heritage, as such items are often difficult to secure in open or partially accessible environments.

Spokespersons for Fort Morgan did not respond to an email seeking comment. The sheriff's office said the institution declined to press charges, and all artifacts were returned to the fort.