Prosecutors in Ankara issued arrest warrants for 110 active duty personnel in the air force, state-run news agency Anadolu said, as part of a probe into followers of US-based Muslim cleric Fethullah Gulen.

Police launched operations in 16 provinces including Ankara while those detained in other cities would be taken to the Turkish capital.

Five of those sought by police were pilots while three were colonels, the agency added.

Turkey claims Gulen ordered the attempted overthrow of President Recep Tayyip Erdogan on July 15, 2016 but he strongly denies the charges.

Over 77,000 people including military personnel, teachers and judges have been arrested over suspected links to Gulen under the two-year state of emergency imposed five days after the coup bid. The government ended the emergency this July.

Western allies have expressed concern over the scale of the crackdown which saw over 140,000 people suspended or sacked from the public sector.

In the face of stringent criticism, Ankara has insisted the raids are necessary to remove the "virus" that is the Gulen movement's infiltration of key Turkish institutions.

Gulen, who has lived in self-imposed exile in Pennsylvania since 1999, denies this and insists his movement is peaceful, and promotes moderate Islam and secular education.