Two people have been killed and several others are injured after a gunman opened fire at a major US navy base in Florida.
The gunman was shot dead a few minutes after the shooting at the Naval Air Station in Pensacola, Escambia Sheriff's spokeswoman Amber Southard confirmed.
Two other people were killed, the navy said in a statement, without providing further details.
According to local news channel WEAR TV, the sheriff's deputies at the base fatally shot the gunman.
Pensacola Police spokesman Mike Wood confirmed that police responded to the gunman, adding that at least six injured people were taken to the trauma centre of the Ascension Sacred Heart Hospital Pensacola.
News outlets were reporting that 11 people have been taken to area hospitals.
The base is on lockdown and all gates have been closed.
Escambia County Commissioner Jeff Bergosh, who works at the navy base as a civilian contractor, told the Pensacola News Journal he was in line to go through the gate on Friday morning when it was shut down due to the active gunman report.
"There's probably been 100 or so various law enforcement vehicles zooming down the wrong side on Navy Boulevard," Mr Bergosh said. "There's been ambulances, fire trucks. It's my understanding there's multiple casualties."
NAS Pensacola employs more than 16,000 military and 7,400 civilian personnel, according to its website.
It is near Florida's border with Alabama and is a major training site for the navy, as well as home to its aerobatic flight demonstration squadron the Blue Angels. The base also ncludes the National Naval Aviation Museum - which is a popular tourist attraction.
The shooting comes two days after a sailor shot three civilians at the historic Pearl Harbour military base in Hawaii. He killed two people before taking his own life.