A US Navy sailor has shot and killed two civilians working at Hawaii's historic military base of Pearl Harbor, and injured a third, military officials say, before fatally shooting himself.
Authorities did not identify the victims and the gunman or give a motive for the shooting, but media said the dead were all men.
The gunman died of "an apparent self-inflicted gunshot wound", military officials told a news briefing, adding that the third victim was in stable condition in hospital.
"We have confirmed that two (victims) are deceased," said the regional commander, Rear Admiral Robert Chadwick.
"One is in stable condition in a local hospital. I can also report that the shooter, who has tentatively been identified as an active-duty sailor assigned to USS Columbia SSN 771, is also deceased by an apparent self-inflicted gunshot wound."
On Twitter, base officials had earlier said all three victims were civilians working for the US Department of Defence.
"I join in solidarity with the people of Hawaii as we express our heartbreak over this tragedy and concern for those affected by the shooting," Governor David Ige said on Twitter.
"Details are still emerging as security forces at Joint Base Pearl Harbor-Hickam investigate," he added, using the official name of the base.
The White House had contacted him to offer assistance from federal agencies as needed, Ige said.
A White House spokesman said, "The president has been briefed on the shooting...and continues to monitor the situation."
The base, a combined US Air Force and Navy installation 13km from the state capital of Honolulu, was placed on lockdown for about two hours after the incident at about 2.30pm on Wednesday.
An unidentified witness told Hawaii News Now (HNN) that he had heard gunfire near Drydock 2 of the base and looked up from his desk to see the gunman put the weapon to his head and shoot himself.
The gunman was wearing a US Navy uniform, the witness added in the on-air interview.
Hawaii police detectives are assisting the military in an investigation that could require as many as 100 witnesses to be interviewed, HNN and other media said.
The incident comes three days before the 78th anniversary of the December 7, 1941 attack on the naval base that led the United States to declare war on Japan and enter World War II.
Australian Associated Press
