Police arrested 28 suspects across Turkey as part of an ongoing investigation into the Fetullah Terrorist Organization (FETÖ), according to a police official.
Earlier, the Chief Public Prosecutor’s Office in Ankara had issued arrest warrants for 81 people for use of ByLock.
ByLock is a mobile app that had been used by FETÖ members during the July 15, 2016, defeated coup.
The app have been cracked by Turkish security agencies, allowing them to identify tens of thousands of apparent FETÖ supporters.
The countrywide arrests were made after police carried out Ankara-based operations against FETÖ in 13 provinces.
Suspects worked at FETÖ-linked schools and private teaching institutions, the official, who spoke on condition of anonymity due to restrictions on talking to the media, said.
FETÖ is behind a long-running campaign to overthrow the state through the infiltration of Turkish institutions, particularly the military, police, and judiciary.
FETÖ and its U.S.-based leader Fetullah Gülen orchestrated the defeated coup of July 15, 2016, which left 250 people martyred and some 2,200 injured.