Turkish police have detained the editor-in-chief of opposition secularist newspaper Cumhuriyet over alleged links to a US-based cleric and Kurdish militants.
Police also said homes of the paper's executives and writers were being searched, broadcaster CNN Turk and other media reported.
Prosecutors have issued detention warrants for a total of 13 executives and writers at the newspaper including editor Murat Sabuncu and the paper's chairman, CNN Turk reported.
It also said one of its writers had been detained in the capital Ankara.
The pro-government Yeni Safak newspaper said on its website they were being investigated over alleged links to US-based cleric Fethullah Gulen, who has been accused by Ankara of orchestrating a failed coup in July, as well as links to Kurdish militants.
Previous Cumhuriyet editor Can Dundar was sentenced to six years for publishing state secrets involving Ankara's Syria operations.
His conviction sparked censure from rights groups and Western governments worried about worsening human rights in Turkey under President Tayyip Erdogan.
The police operation comes after Turkey dismissed a further 10,000 civil servants and closed 15 more media outlets over the weekend, over suspected links with militant groups and Mr Gulen.
More than 100,000 people had already been sacked or suspended, and 37,000 arrested since the abortive putsch in an unprecedented crackdown that Erdogan said was crucial to wipe out Gulen's network from the state apparatus.