Mayor Barbara Sharief said there was one shooter who was now in custody.
"Confirmed: Shooting at Fort Lauderdale-Hollywood International Airport with multiple people dead. One subject in custody," the Broward County Sheriff's office said in a tweet.
Mayor Barbara Sharief said there was one shooter who was now in custody. The attack was not yet known.
"He was a lone shooter, and we have no evidence at this time that he was acting with anyone else. He is in custody, and we are currently investigating," Sharief told CNN.
The airport has been shut down, she added.
Governor Rick Scott said he was rushing to the airport to be briefed on the shooting.
Fort Lauderdale is a major tourist hub and beach resort in the greater Miami area.
Television footage showed passengers running to safety, and others gathered on the tarmac.
"There is an ongoing incident in Terminal 2, Baggage Claim," the airport tweeted.
Ari Fleischer, a former White House spokesman, tweeted: "I'm at the Ft. Lauderdale Airport. Shots have been fired. Everyone is running."
In another tweet, he cited police as saying there was one shooter and five victims.