Latest example of Turkey's deteriorating stability
Gulen, a reclusive figure who leads a popular movement called Hizmet, said anyone could have masterminded the coup attempt: nationalists, the opposition. He denied any involvement.
"It could be anything," Gulen told journalists through a translator.
"I have been away from Turkey for 16 years," he said.
Whoever was responsible, the uprising is the latest worrying example of deteriorating stability in a country once promoted to the wider Muslim world as a model of democratic governance and economic prosperity.
Some 14 years after Erdogan's political party swept to power in elections, Turkey teeters on the brink.
At the heart of Erdogan's rivalry with Gulen is a fundamental division in Turkish society between secularists -- some within the country's top military brass -- and Islamists, including the president's AKP party.
Thousands of military officers have been arrested, including the commander of Turkey's 2nd Army, Gen. Adem Huduti.
On Saturday, the Pentagon said U.S. officials were working with Turkey to resume air operations at Incirlik Air Base.
"In the meantime, U.S. Central Command is adjusting flight operations in the counter-ISIL campaign to minimize any effects on the campaign," Pentagon spokesman Peter Cook said.
Key air base closed
For now, American airstrike missions from the base have been halted. Turkish officials told the United States the airspace has been closed until they can make sure all Turkish air force elements are in the hands of government forces, a U.S. defense official told CNN on Saturday.
Still, a small number of U.S. planes on missions before the airspace closed were allowed to land at Incirlik, the official said.
Earlier, the U.S. consulate in Adana reported that power to the base had been cut and authorities prevented movement on and off the site.
Cook said U.S. facilities were operating on internal power and the power shutdown did not affect base operations. Defense department personnel in the area were "safe and secure," he said.
The base is home to the Turkish Air Force and the U.S. Air Force's 39th Air Base Wing, which includes about 1,500 American personnel, according to the base website.