The Navy sailor who shot three civilian employees, killing two of them, before taking his own life Wednesday at Pearl Harbor Naval Shipyard has been identified as 22-year-old Gabriel Romero, according military officials and multiple published reports.

»MORE: Sailor kills 2, himself in attack at Pearl Harbor shipyard

Romero reportedly was an active-duty sailor assigned to the USS Columbia, a fast-attack submarine that is in dock at the base for maintenance, according to Hawaii News Now.

It wasn’t immediately known what type of weapon was used or how many shots were fired, officials say.

Names of the two victims won’t be released until their relatives have been notified.

The commander of Navy Region Hawaii, Rear Adm. Robert Chadwick, said he didn’t know the motive behind the shooting that left a third civilian Department of Defense employee hospitalized.

It also wasn’t known if the sailor and the three male civilians had any type of relationship, or what the motive was for the shooting, Chadwick said.

“We have no indication yet whether they were targeted or if it was a random shooting,” Chadwick told The Associated Press.

Personal weapons are not allowed on base at Joint Base Pearl Harbor-Hickam.

The base was put on lockdown about 2:30 p.m. Wednesday after the first reports of an active shooter were received. The base reopened a few hours later. The shooting remains under investigation.

The shipyard repairs, maintains and modernizes the ships and submarines of the U.S. Pacific Fleet, which is headquartered at Pearl Harbor. The base is the home port for 10 destroyers and 15 submarines. It also hosts Air Force units.

— Information from The Associated Press was used to supplement this report.