Pensacola shooter dead, several injured in gunfire at naval air station

Emergency responders near the Naval Air Base Station in Pensacola, Florida. Photo / AP

A mass shooting at a US naval base has left at least two people dead and several more injured for the second time in two days.

The latest deadly shooting unfolded when a gunman opened fire at Naval Air Station Pensacola, in Florida, on Friday around 7am. The base was immediately placed on lockdown.

At least two people were killed – including the shooter, according to the US Navy.

About 45 minutes after the first shots rang out, the Escambia County Sheriff's Office confirmed on Facebook that the shooter was dead.

"Multiple injured personnel have been transported to local hospitals. We will continue to work closely with law enforcement agencies," Lieutenant Commander Megan Isaac said in a statement.

Baptist Health Care received eight patients from the shooting, according to spokeswoman Kathy Bowers. She said no further information was immediately available on their conditions.

Navy Captain Tim Kinsella briefs members of the media following a shooting at the Naval Air Station in Pensacola, Florida. Photo / AP

The US Navy said one additional fatality has been confirmed and that an "unknown number of injured people were being transferred to local hospitals."

The gunman was shot and killed by deputies at the base, according to Channel 3 News.

#UPDATE: Active shooter is deceased.

One additional fatality has been confirmed. Unknown number of injured people being transferred to local hospitals.

— U.S. Navy (@USNavy) December 6, 2019

#UPDATE: A second victim has been confirmed deceased.

— U.S. Navy (@USNavy) December 6, 2019

FBI personnel from Pensacola, Jacksonville and Mobile, Alabama, are responding to the station, an FBI spokeswoman said.

US President Donald Trump has been briefed on the situation, according to a White House spokesperson.

Naval Air Station Pensacola employs more than 16,000 military and 7,400 civilian personnel, according to the base's website.

The fatal incident comes just two days after an active-duty sailor opened fire with his M4 service rifle at the Pearl Harbor Naval Shipyard in Hawaii, killing two and wounding a third before turning the gun on himself.

The shooter was later identified as 22-year-old Petty Officer Gabriel Romero.

Romero was a crew member aboard the submarine USS Columbia, which was dry-docked at the shipyard for maintenance.

The incident took place about 2.30pm local time.

"Base security and Navy investigative services are currently investigating," the base said.

"The names of the victims will not be released until the next of kin have been notified."

All three were male Department of Defence civilian workers, authorities said.

Rear Admiral Robert Chadwick, commander of Navy Region Hawaii, said: "our thoughts are with the families of the victims and everyone involved".

"This is certainly a tragedy for everyone here," he continued.

He said it wasn't immediately clear whether the gunman knew the victims or if they were targeted at random.