As many as 176 serving military officers will be arrested in Turkey over suspected links to the network that Ankara says was behind a failed coup in 2016.
In a statement, the Istanbul chief prosecutors' office said those facing arrest included a colonel, two lieutenant colonels, five majors, seven captains and 100 lieutenants.
Ankara says US-based Fethullah Gulen masterminded the failed putsch on July 15, 2016.
He has denied any involvement.
More than 77,000 people have been jailed pending trial and about 150,000 civil servants, military personnel and others have been sacked or suspended from their jobs during the three-year crackdown.

Trump says US could restart Iran strikes 'if they misbehave'
Israeli military urge southern Lebanon residents to evacuate
Russia's Primorsk port hit as Ukraine launches wave of drone strikes
At least six dead, thousands displaced as heavy rains hit northeastern Brazil
Austrian police arrest man over poisoned baby food case