Updated: 1/15/20 12:00 p.m.
Three civilians were released Wednesday after they were arrested when Navy personnel found a mortar round, later determined to be non-explosive, inside their vehicle, according to Pearl Harbor spokesman Chuck Anthony.
The three were stopped at the Nimitz Gate with no authorization to enter the base. When the gate guard had the vehicle turned around, the guard noticed the smell of drugs and saw the ordnance in the car.
It's not clear what the trio planned to do or where they wanted to go when they were stopped Tuesday night, Anthony said.
Anthony said a training mortar has no exploding component.
Joint Base Pearl Harbor-Hickam was shut down to traffic around 10:30 p.m. Tuesday while a bomb squad investigated. The base's gates were closed for about two hours, but no one was allowed through the Nimitz Gate until early Wednesday. There were no injuries.
Naval Criminal Investigative Service is investigating and took custody of the three suspects, Anthony said. He said they were later released.
An NCIS spokesman said he would look into whether there were any details he could release about the investigation.
The base is home to a naval shipyard where an active-duty U.S. sailor opened fire on three civilian employees in December, killing two of them. Officials have said the sailor, whose submarine was docked at Pearl Harbor, then took his own life.
The shooting happened days before dignitaries and veterans attended the base's ceremony to mark the 78th anniversary of the Japanese attack on Pearl Harbor.