Turkey jails 17 foreigners, in latest IS suspects sweep
The suspects, whose nationalities were not given, were arrested in Ankara and taken for interrogation by counter-terrorism officers, state Anadolu News Agency said.
Turkey has highlighted its efforts to crack down on IS militants following the assassination of its leader Abu Bakr al-Baghdadi by the United States last week.
Turkish officials said they arrested Baghdadi's sister this week, and announced they had been holding his wife since last year.
President Recep Tayyip Erdogan said Thursday that members of Baghdadi's entourage had been arrested seeking to enter Turkey and that several - "close to double figures" - had been arrested.
He said 13 members of the entourage were currently in Turkish detention.
In the early years of the Syrian conflict when Turkey was keen to see the overthrow of President Bashar al-Assad, it was accused of failing to prevent the passage of jihadists over its border.
That changed following a series of attacks within Turkey, and Ankara joined the US-led anti-IS coalition in 2015.
It has again been accused of undermining the battle against IS in recent weeks with its military offensive against Kurdish forces in northern Syria, who have been the key ground force against IS and were crucial to locating Baghdadi.