State broadcaster TRT reported that the detainees included three foreign nationals. The nationalities of the foreign detainees were not revealed by the state media.
No one has so far claimed responsibility for the attack. The terrorists targeted one of Europe's busiest transit hubs. The investigators were yet to reveal what they know about the suicide bombers.
The airport was attacked by three terrorists on Tuesday night. The trio opened fire and detonated explosives, killing 42 people and injuring hundreds more.
According to officials, the attackers arrived at the airport with rifles and suicide bomb vests. Two suicide bombers opened fire and detonated their bombs at the international terminal building. The third died in the parking lot, where he detonated himself.
The attackers followed the strategy adopted by the attackers in Brussels as they took a taxi to the airport.
After the attack, the taxi driver was interrogated by police but was later released, Turkish state news agency Anadolu reported.
Turkish President Recep Tayyip Erdogan proclaimed the terror attack "will not divide or split our country." Officials blamed the attack on ISIS.
Erdogan added that terrorists are not true Muslims because they are killing dozens of civilians, including women and children. "This is not Islamic. Taking one person's life means going straight to hell," he said. "No terrorist organization will come between what we are."
"All information and evidence" points to ISIS, Interior Minister Efkan Ala said. "But nothing is for certain."