- Police declined to identify the shooter or whether or not they were in the military.
- Federal agencies are investigating, authorities said, including the FBI and the Bureau of Alcohol, Tobacco, Firearms and Explosives.
A gunman opened fire on Friday at a US naval base -- the second such shooting in as many days -- killing three people before being shot dead by police, officials said.
The shooting, which took place at Naval Air Station Pensacola in Florida, left seven people injured including two sheriff's deputies who responded to the attack, one of whom was shot in the knee, the other in the arm.
Police received their first call about the shooting shortly before 7:00 am (1200 GMT), Escambia County Sheriff David Morgan told a press conference. One of the responding deputies eventually killed the attacker.
"Walking through the crime scene was like being on the set of a movie," Morgan said. "You don't expect this to happen at home."
Police declined to identify the shooter or whether or not they were in the military. They also would not say if they thought the act was motivated by terrorism.
Commanding officer Timothy Kinsella said the base's security forces first responded to the shooting before outside police agencies arrived.
The facility, which is used for training and made up mostly of classrooms, "is shut down until further notice," he said.
Witnesses to the shooting described a chaotic scene as police rushed to respond.
"There's probably been 100 or so various law enforcement vehicles" driving through opposing traffic towards the base, Jeff Bergosh, a county commissioner who is a contractor at the facility, told the Pensacola News Journal newspaper.
White House press secretary Judd Deere said President Donald Trump "has been briefed on the shooting at Pensacola Naval Air Station... and is monitoring the situation."