SKY News reports that three suicide bombers opened fire before blowing themselves up at the international terminal.
Turkish officials say 28 people have died in the attack, but some estimates have placed the death toll much higher.
Istanbul Governor Vasip Sahin described the explosions, which occurred at 9.50pm Tuesday (4.50am Wednesday AEST), as a “major co-ordinated” attack, according to News.com.au.
Traveller Laurence Cameron described the scene to CNN saying “It was just a massive crowd of screaming people. Some were falling over themselves. A poor chap in a wheelchair was just left, and everyone just rushed to the back of the building, and then people ran the other way and no one really seemed to know what was going on. Where you normally hail a taxi, that is where the attack happened. The ground is just kind of shredded. There is bloodstains on the floor as well."