Turkey's state-run news agency says authorities have issued detention warrants for 35 journalists and media workers as part of the country's ongoing crackdown on people suspected of ties to U.S.-based Muslim cleric Fethullah Gulen.

Anadolu Agency says police were on Thursday carrying out raids in Istanbul to detain the suspects who allegedly used an encrypted messaging app that authorities say was favored by Gulen's followers to communicate with each other.

Those detained so far include Burak Ekici, a journalist working for the opposition Birgun newspaper, Anadolu said.

Turkey accuses Gulen of masterminding last year's failed military coup. More than 50,000 have been arrested, most accused of links to the coup. More than 110,000 people have also been sacked from government jobs.

Gulen denies involvement in the coup.