The Chief Prosecutor's Office in Ankara on Thursday issued arrest warrants for 12 teachers over their suspected links to the Fetullah Terrorist Organization (FETO), the terror group behind the defeated 2016 coup bid in Turkey.

The teachers were working at FETO-linked schools shut down following the coup attempt.

Eleven suspects allegedly used the terror group’s encrypted messaging application ByLock.

Separately, four FETO-linked suspects were held in the northwestern Edirne province.

FETO and its U.S.-based leader Fetullah Gulen orchestrated the defeated coup attempt of July 15, 2016, which left 251 people martyred and nearly 2,200 injured.

Ankara also accuses FETO of carrying out a long-running campaign to overthrow the Turkish state through the infiltration of state institutions.