While 21 suspects, including active-duty members of the Turkish Armed Forces, have been taken into custody, security forces are still looking for the remaining one suspect.
Of the suspects detained, 9 were colonels and the others were non-commissioned officers, the 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.