Istanbul police detained at least 34 Daesh-linked foreign nationals in counterterror operations carried out in six districts early Sunday.
The suspects were reportedly planning to carry out attacks and had previously fought for the terrorist group.
Counterterror squads raided seven addresses in Tuzla and Ümraniye districts on the Asian side, as well as Bayrampaşa, Zeytinburnu, Esenyurt and Başakşehir districts on the European side.
Police confiscated digital material and organizational documents, reports said.
The detainees are expected to be deported following procedures.
Turkey has been targeted by a wave of deadly attacks since 2015 by Daesh and PKK terrorists.
Turkey has deported more than 5,000 Daesh suspects and 3,290 foreign terrorists from 95 different countries in recent years, while dismantling terror cells and safe houses providing logistical assistance to the terrorist group in Syria and Iraq or plotting attacks inside the country.
The country's efforts against Daesh made it a primary target for the terrorist group, which carried out numerous gun and bomb attacks targeting security forces and civilians, including the country's deadliest terror attack, which killed 102 people and wounded 400 others through a twin suicide bombing at a rally in capital Ankara, on October 10, 2015.