They were arrested in Adana in southern Turkey after authorities raided 40 locations.
Turkish police detained 30 people with alleged links to Daesh in the southern province of Adana, the Dogan News Agency reported on Friday.
The security services frequently carry out raids on safe-houses harbouring suspected terrorists. In August, Turkey launched a military operation called Euphrates Shield in northern Syria to help opposition fighters expel Daesh from the area.
Backed by helicopters, counter-terror squads on Friday carried out simultaneous raids on 40 addresses in Adana, using battering rams to break open doors, Dogan reported.
The suspects were taken to the province's police headquarters after undergoing routine health checks.