Two victims have died after a shooting at the historic military base at Pearl Harbour in Hawaii, military officials say.
A third victim is in stable condition after being hospitalised while the shooter, a US Navy sailor, also died from "an apparent self-inflicted gunshot wound", the officials said in a press briefing after Wednesday's incident.
Joint Base Pearl Harbour-Hickam said on Twitter that the three shot victims were all 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 Harbour Hickam investigate."
Mr Ige said the White House had contacted him to offer assistance from federal agencies as needed.
"The president has been briefed on the shooting at Joint Base Pearl Harbour-Hickam in Hawaii and continues to monitor the situation," a White House spokesman said.
The base, which was formed by the merger of Pearl Harbour Naval Station and Hickam Air Force Base, was placed on lockdown for about two hours following the incident at about 2.30pm on Wednesday.
An unnamed witness told Hawaii News Now in an on-air interview that he had heard gunfire near Drydock 2 at the base and looked up from his desk to see the gunman put a gun to his head and shoot himself.
An unidentified male sits outside the the main gate. Source: AP
The gunman was wearing a US Navy uniform, the witness told the station.
Joint Base Pearl Harbour-Hickam is a combined US Air Force and Navy Installation located 13km from Honolulu.
An unidentified male is taken away on a stretcher. Source: AP
The incident comes three days before the 78th anniversary of the 7 December 1941 attack on the naval base that led the United States to enter World War II by declaring war on Japan.
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