At least 13 suspects were detained in the raids in Istanbul, with more in the western coastal city of Izmir.
Turkey believes ISIS was behind June 28 suicide gun and bomb attack that left 42 people dead and more than 230 injured.
More details of the victims have emerged, many of them airport workers.
A Turkish official told AFP: “Earlier today, the police raided 16 locations to detain 13 IS suspects, including three foreign nationals.”
Turkish media said counter-terrorism police had raided several areas of Istanbul – including Pendik, Basaksehir and Sultanbeyli.
Arrests were also reported in Izmir, where at least nine people were detained, accused of financing, recruiting and providing logistical support to ISIS.
Separately, Turkish media reported that security forces had killed two suspected ISIS militants on the Syrian border on June 25. They said one was planning an attack on the capital Ankara or the city of Adana.
No-one has yet said they carried out the airport attack.
The Hurriyet newspaper identified one of the three bombers as a Chechen but there is no official confirmation.
Turkey’s PM Binali Yildirim has said again that “our thoughts on those responsible for the attack lean towards Islamic State”.
President Recep Tayyip Erdogan declared Wednesday a national day of mourning and said the attack should serve as a turning point in the global fight against militant groups.
Detailing the attack, Binali Yildirim said the three men had wanted to pass through the security system but on seeing the controls “took their weapons out of their suitcases and opened fire at random at the security check”.
One attacker detonated his explosives downstairs in the arrivals terminal, Turkish officials said.
The second went upstairs and set off his explosives there while the third waited outside as passengers fled. He then detonated his explosives, causing the most casualties.
A Kalashnikov assault rifle, a handgun and two grenades were found on the bodies, Turkish media said.
In addition to the 42 killed, more than 230 people were injured and dozens remain in critical condition in hospital.
The assault on Ataturk airport – Europe’s third busiest – is the sixth major attack in 2016 targeting either Istanbul or Turkey’s capital, Ankara.
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