Turkish President Recep Tayyip Erdogan gestures during a news conference to present the outcome of the G20 leaders summit in Hamburg, Germany. PHOTO: AFP
Seventeen foreigners were among those detained, state-run Anadolu news agency said, without giving details of their nationalities.
Police seized several electronic devices and documents during the operation in nine different Istanbul districts, the agency said.
Officers suspected those detained had links to "people in conflict zones", Hurriyet daily reported, but not saying in which countries.
Turkey has been hit by a series of attacks in the last 18 months blamed on IS and Kurdish militants.
The last major IS attack was during New Year's Eve celebrations at an elite Istanbul nightclub where a gunman killed 39 people, most of them foreigners.
There have been frequent police raids since against IS including one on July 12 in the central Turkish province of Konya when police killed five alleged IS extremists.
The Turkish border with Syria was previously a key transit point for IS recruits and supplies before Turkey tightened security and launched a military operation to clear the militants from the frontier last August.
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