Greg Barton from Deakin University told Fairfax Media that the March attack at Brussels airport had been a "proof of concept" for the group that had been replicated in Turkey overnight.

Passengers leave Istanbul's Ataturk airport after a suicide bomb attack. Turkey is likely to come under increasing pressure from the militant group. Credit:Defne Karadeniz

"Brussels was hurried and messy … but it was still very effective as a kind of proof of concept to ISIL … You just go in the front door and you have made it. Airports are set up to deal with an enormous number of people. You've got globalised, international travellers at a high profile location and which is a soft target."

In the early period of the Syrian civil war, Turkey had prioritised the defeat of the regime of Bashar al-Assad and taken a tolerant view of so-called "foreign fighters" passing through its territory into Syria to join rebel groups.

But with Turkey having opened its air bases to US forces – under pressure from its NATO ally Washington – and more recently seeking to improve relations with Russia, which is strongly supporting the Assad regime, Islamic State had stepped up attacks on Turkey in an apparent bid to impose a cost on the country, said Rodger Shanahan, a former Army officer now with the Lowy Institute.