Former White House Press Secretary Ari Fleischer said in a tweet: “I’m at the Ft. Lauderdale Airport. Shots have been fired. Everyone is running.”
A Miami TV station tweeted footage claiming to be filmed from inside the baggage terminal.
The video shows several injured people laying on the floor, as witnesses shout for medical help.
A witness told NBC News the gunman was shot by police less than a minute after the shooting began.
“He was gunned down by police,” Mark Lea from Minneapolis told the network.
“It was absolutely surreal,” he said.
“People were scared and frantically running to avoid being shot. People were tripping over each other. They were trying to make a fast exit out of the door.”
Florida Governor Rick Scott is travelling to the airport to be briefed by law enforcement.
Federal aviation authorities issued a “ground stop” notice, barring flights from leaving or entering the airport.
Fort Lauderdale is a major tourist hub in the greater Miami area.
Nearby Miami International Airport announced that “extra security measures” have been put in place “out of an abundance of caution”.
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