Turkey’s Justice Ministry has formally requested the U.S. to provisionally arrest Islamic cleric, Fethullah Gulen, accused by Ankara of masterminding failed July 15 coup.

Turkish government-run Anadolu News Agency, which reported this on Tuesday, recalled that Turkey had requested Gulen’s extradition and had been pressuring the U.S. to detain him.

Gulen has lived in the U.S. since 1999.

Washington had said that it wanted to see concrete proof that the cleric was involved in the putsch.

The suspected coup planner 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.

It has also been 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.