Three individuals were detained after a security guard at Joint Base Pearl Harbor-Hickam spotted potential ordnance in their vehicle at Nimitz Gate on Tuesday night, prompting security forces to temporarily shut down all gates at the base, an official said.

Spokesman Chuck Anthony said an explosive ordnance disposal team identified the ordnance as a live training mortar round. The mortar had a fuse and could fly but would not explode on contact. The round did not have “high explosives,” he said.

Anthony said as of Wednesday afternoon the three individuals had been released.

Security responded to a vehicle occupied by three civilians at Nimitz Gate at about 10:30 p.m. Tuesday that did not have authorized access at the base.

When the gate guard requested the driver to turn around, the guard noticed the smell of marijuana and saw potential ordnance in plain sight in the car, Anthony said.

The ordnance disposal team immediately responded to the scene while security forces shut down access to the base at all gates.

The team removed the 10-inch-tall mortar from the vehicle for disposal. No injuries were reported.

Security forces reopened the O’Malley Gate shortly after midnight. All gates reopened to normal traffic shortly before 4 a.m. Wednesday.

Anthony said the three individuals were temporarily in the custody of the Naval Criminal Investigative Service. The three individuals were believed to have mistakenly arrived at the gate.

Their ages and genders were not immediately available.