No injuries have been reported in connection with the incident.
Earlier, a rental car employee told WFTV he heard what sounded like gunfire, but no shots had been fired, airport spokeswoman Carolyn Fennell said.
Images posted on social media showed a heavy police presence in the area and passengers were worried about missing flights. The Florida Highway Patrol tweeted that all roads to the airport were shut down, with "zero exceptions." Authorities warned people to stay in their vehicles and away from law enforcement officers.
Earlier this year, authorities say an Alaska man killed five people inside a baggage claim area at the Fort Lauderdale-Hollywood International Airport.