Arrest warrants issued after the suspects were found to have used ByLock, an encrypted messaging app used by FETO members to communicate, officials said.
Since May 2016, Turkey has classified the FETO organization as a terrorist organization under the assigned names Fethullahist Terrorist Organization and Parallel State Structure.
After the failed coup attempt in 2016, the government of Turkey blamed the group for the coup and authorities have arrested thousands of soldiers and judges who have links to the organization.