A US army veteran who said the government was controlling his mind has shot dead five people at Fort Lauderdale airport in Florida.

Authorities have identified the suspected shooter as Esteban Santiago, 26, from Anchorage, Alaska.

Santiago served in Iraq with the National Guard, before being demoted and discharged last year for poor performance.

Relatives said he had a history of mental health problems, and had recently been getting psychological treatment.

Santiago had reportedly walked into the FBI office in Anchorage in November to say that the US government was controlling his mind, and making him watch Islamic State videos.

Santiago had been questioned by agents before police took him for a mental health evaluation, but the official said he had not seemed intent on hurting anyone.

On Friday, he arrived at Fort Lauderdale just before 1pm local time (6pm Irish time) on a flight from Minnesota, police said.

Reportedly dressed in a Star Wars t-shirt, he took a 9mm semi-automatic handgun from his checked luggage and began firing at people.

Broward County commissioner Chip LaMarca said on Facebook: "He claimed his bag and took the gun from baggage and went into the bathroom to load it. Came out shooting people in baggage claim."

Mark Lea told MSNBC: "People started kind of screaming and trying to get out of any door they could or hide under the chairs. He just kind of continued coming in, just randomly shooting at people, no rhyme or reason to it."

As well as the five dead, eight others were injured in the shooting.

Santiago was taken away by police after throwing his gun down and lying spread-eagle on the ground, according to a witness.

Sheriff Scott Israel told a news conference that it was uncertain whether the shooting was an act of terror, and the suspect is now being interviewed by FBI agents and detectives.

Image: Joined by law enforcement officials, Florida Gov. Rick Scott (center) speaks during a news conference outside Fort Lauderdale-€“Hollywood International Airport (AP Photo/Wilfredo Lee)

Florida governor Rick Scott told reporters the shooting was "a senseless act of evil". Fort Lauderdale-Hollywood International Airport was closed indefinitely, but was expected to reopen sometime on Saturday morning.

Flying with guns in the US is legal, as long as they are kept in a locked hard-sided container as checked baggage only, under TSA rules. Ammunition is not allowed in cabin baggage, but is allowed in checked baggage.