Seven suspected Daesh terrorists, who were detained late December, were remanded in custody in eastern Van province while dozens of other suspected were held in Istanbul on Thursday, security officials said.
According to a statement from the police department of Van -- an eastern province in Turkey -- the suspects were among 23 people who had been arrested on Dec. 28, 2017, during simultaneous operations in Van and southeastern provinces of Diyarbakir and Mardin.
The suspects were believed to be linked to the conflict zones in Syria and Iraq.
Sixteen others were released under judicial control, the statement added.
In another operation in Turkey's most populous city of Istanbul, 42 foreigners were arrested in raids at different addresses across 12 districts including Basaksehir, Fatih, and Zeytinburnu for being linked to Daesh.
An undisclosed number of organizational documents and digital materials were also seized during the raids, an anonymous security source said.
Suspects were accused of being members of the terrorist Daesh and plotting terror act, the source, who spoke on condition of anonymity, added.
More than 300 people have lost their lives in Daesh attacks in Turkey so far, where the terrorist organization has targeted civilians in suicide bombs, rocket and gun attacks.
Turkish security forces have been involved in a long-running campaign to thwart Daesh attacks.
Reporting by Necat Hazar, Halil Demir:Writing by Burcu Arik