Turkey's counterterrorism police have detained over 440 people for alleged links to the Islamic State (IS) extremist group.
The detentions mark the biggest roundup to target the IS organization in Turkey.
The state-run Anadolu Agency said that 60 IS suspects, the majority of them foreign nationals, were taken into custody early on February 5 in the capital, Ankara, while 150 were arrested in Sanliurfa Province near the Syrian border.
The predawn operations spanned several cities including Istanbul and Gaziantep, near the border with Syria.
Nine suspects who were allegedly preparing an attack in the northwestern city of Izmir were also arrested.
Turkey has stepped up its counterterrorism efforts after a failed coup attempt and dozens of bloody attacks linked to IS or Kurdish militants last year.
Some of those detained were reportedly active in conflict zones and recruitment efforts for IS.
On August 24, Ankara sent ground troops to support Turkey-backed Syrian opposition forces in clearing a border area of IS militants and to curb Syrian Kurdish territorial expansion.