Turkey's Justice Ministry formally requested that the United States provisionally arrest Islamic cleric Fethullah Gulen, who the government in Ankara claims orchestrated the failed July 15 coup attempt, the state-run Anadolu news agency reported Tuesday.
Turkey has already requested Gulen's extradition and has been pressuring the US to detain him. Gulen has lived in the US since 1999.
Washington has said it wants to see concrete proof that the cleric was involved in the putsch.
The preacher was a one-time ally of Turkish President Recep Tayyip Erdogan but the two fell out in recent years.
Turkey has been suspending and firing alleged sympathizers of Gulen from the civil service and arresting people in the private sector, though the purges appear to be extending far beyond those who might have been involved in the coup attempt.