Prosecutors had previously issued arrest warrants for 34 people suspected of having financial ties to the terror group, as well as for using ByLock, its encrypted messaging app, said the sources, asking not to be named due to restrictions on speaking to the media.
Operations to arrest the remaining suspects are ongoing.
FETO and its U.S.-based leader Fetullah Gulen orchestrated the defeated coup of July 15, 2016, which left 251 people martyred and nearly 2,200 injured.
Ankara also accuses FETO of being behind a long-running campaign to overthrow the state through the infiltration of Turkish institutions, particularly the military, police, and judiciary.
