An eyewitness to the Fort Lauderdale Airport shooting has described the moment a "silent shooter" gunned down travellers.

Earlier, officials said there were unconfirmed reports of additional shots fired at the international airport in Fort Lauderdale, Florida, after a gunman killed five people and wounded eight there.

On Friday afternoon, the Broward County sheriff's office said on its Twitter account: "Active search: Unconfirmed reports of addt'l shots fired on airport property."

At a later press conference Sheriff Scott Israel confirmed that the scene is still active at the time of reporting. Israel said that their was no confirmed incident of gunshots other than those fired at terminal 2 of the airport.

The Sheriff confirmed there was only one suspect in custody and would not comment on the type of weapon used. Israel said there is currently no indication it was a terror attack.

Mark Gale, Director of Fort Lauderdale Airport, confirmed that the airport remained shut down as they worked with authorities to investigate the attack.

John Schlicher, who was in the airport at the time a gunman wearing a Star Wars T-shirt carried out the attack, told Fox News the man said nothing as he opened fire.

"It was very surreal," John Schlicher told the TV station. "He did not say a word. He was shooting people that were down on the ground, too."

Authorities reportedly shouted for people to take cover as they realized there was a shooter on the premises.

Gene Messina, who was waiting for friends to get off a flight, told the Sun Sentinel people screamed and fled as a man pulled out a gun, in an attack that has left at least five people dead.

"All of a sudden I heard screaming and running, people coming from security, yelling 'He has a gun!He has a gun!'"

Former White House press secretary Ari Fleisher, who was in the airport at the time of the attack, tweeted to his followers: "I'm at the Ft. Lauderdale Airport. Shots have been fired. Everyone is running."

He later tweeted the situation appeared to have calmed down, with police confirming a suspect, named by US senator Bill Nelson as Esteban Santiago, in an interview with MSNBC, had been taken into custody.

Fort Lauderdale Hollywood International shooting
Photo of a wounded victim after a gunman opened fire inside Terminal 2 of Fort Lauderdale-Hollywood International Airport on 6 January 6, leading to multiple casualties. twitter.com/MxWllSolutions