A US sailor shot and killed two civilian Department of Defense employees at the Pearl Harbor shipyard before taking his own life on Wednesday, the US military said.

A third victim is at a hospital.

The military didn’t release a motive or any identifying information about the sailor. Joint Base Pearl Harbor-Hickam has reopened following a lockdown.

A spokesman told Hawaii News Now earlier that the situation at Drydock 2 has been “contained".

First responders were called to the base about 2:30 p.m. local time. In the minutes after the shooting, base personnel were urged over PA system and with text messages to shelter in place.

The Joint Base Pearl Harbor-Hickam confirmed the details of the shooting on Twitter.

“Officials at Joint Base Pearl Harbor-Hickam report the shooting incident at the Pearl Harbor Naval Shipyard has been secured. One person is confirmed dead. The shooter has been identified as a U.S. Sailor,” it wrote.

“The sailor reportedly shot and injured three Department of Defense civilian workers before shooting [himself]. The incident took place this afternoon at the vicinity of the shipyard’s Dry Dock 2. The base is no longer in lockdown.”

The shipyard is across the harbor from the Pearl Harbor National Memorial, which on Saturday will mark the 78th anniversary of the attack by Japan that propelled the US into World War II.

Pearl Harbor houses the headquarters for the US Pacific Fleet and is the home port for 10 destroyers and 15 submarines.