Four foreign nationals were arrested Thursday in central Turkey for suspected links to the Daesh terrorist organization, according to a police source.

Authorities confiscated a large amount of digital material and documents relating to the terrorist group during a search of the suspects’ residences, said the source, who asked not to be named due to restrictions on speaking to the media.

One of the suspects was determined to be a wanted senior member of Daesh -- the so-called “emir” of Iraq’s Tal Afar district -- and entered Turkey illegally.

More than 300 people have been killed in attacks claimed by Daesh in Turkey, where the terrorist organization has targeted civilians in suicide bomb, rocket and gun attacks in recent years.

Turkish security forces have been involved in a long-running campaign to thwart Daesh attacks.