An Istanbul court on Thursday remanded 28 Daesh suspects in custody as part of a December probe, a judicial source said.
The suspects are charged with "being member of an armed terrorist organization", the source said on condition of anonymity due to restrictions on talking to the media.
The suspects are among 33 people who were arrested Wednesday; of those, one was freed by the prosecutor's office.
Four others were released under judicial supervision on Thursday.
Police operation is ongoing to arrest eight other suspects sought in the probe.
