A Naval Base in San Diego was locked down this week over shooting fears caused by a rather harmless weapon.

Naval Base Point Loma in San Diego was shut down early Thursday morning after the Navy received reports of men with a gun on the base. The base was locked down under a shelter-in-place warning for hours as the matter was investigated. The Naval Criminal Investigative Service (NCIS), FBI, and San Diego police all responded to the base.

According to a Reuters report, the quick investigation found that the scare was caused by two sailors using an Airsoft pellet gun. The men had reportedly been using the weapon to shoot at a mirror located in a parking structure on the base.

The sailors are now in Navy custody. Though the Navy said it does not suspect the men intended to scare or injure anyone, they are “likely” to be charged over the incident. The NCIS is investigating the specifics of the case.

Naval Base Point Loma is a large base made up of several Naval installations consolidated in 1998. The base includes a submarine base and training facilities; the Fleet Intelligence Command Pacific; and the Space and Naval Warfare Systems Command (SPAWAR). According to its website, Naval Base Point Loma’s mission is to “enable and sustain Fleet, Fighter, and Family readiness through consistent, standardized, and reliable shore support while preserving the critical resources necessary to secure the future of our forces.”

This naval base shooting scare comes within months of several high-profile Naval base shootings that were not false alarms. On September 16, 2013, Navy subcontractor Aaron Alexis opened fire at the Washington Navy Yard, killing twelve people. In October another shooter injured two people at a Naval base in Tennessee. Just last month two people were shot and killed aboard the USS Mahan, a ship docked at Naval Station Norfolk off the coast of Virginia.

Image via Wikimedia Commons/U.S. Navy