Five people have been shot dead at Fort Lauderdale-Hollywood International Airport in Florida, with up to 13 taken to hospital, according to officials.
Initial reports suggested only one person had been killed and nine injured, but the Broward County Sheriff's Office later tweeted "multiple people dead".
The shooter, identified by Florida Senator Bill Nelson as Esteban Santiago, has been captured alive, according to the Sheriff's Office. It's believed he acted alone.
Santiago, 26 and a US citizen, was identified by his military ID. He was taken into custody without incident. Police fired no shots in the incident.
The suspect was a passenger who'd checked his weapon in with his baggage, law enforcement officials told the Washington Post anonymously.
He allegedly took the gun into the bathroom to load it, before opening fire in a baggage claim area.
His motive remains unclear.
Former White House press secretary Ari Fleischer was at the airport, and tweeted "everyone is running".
The airport's own Twitter account earlier confirmed an "ongoing incident" was underway.
Fort Lauderdale is the United States' 21st busiest airport. All flights were temporarily suspended.