An Istanbul court on Friday remanded 17 Turkish journalists in custody over links to the US-based preacher Fethullah Gulen who is blamed for this month's failed coup, charging them with membership of a "terror group".

Twenty-one journalists had their cases heard by the court, with four being freed and 17 placed under arrest ahead of trial, the state-run Anadolu news agency said. Those held include the veteran journalist Nazli Ilicak, it added.