Authorities in the capital of Ankara and the western city of Izmir issued arrest warrants for 24 suspects linked to the Gülenist Terror Group (FETÖ). Subsequent operations led to the capture of 19 suspects on Wednesday.

In Izmir, the prosecutors sought the arrest of 19 suspects after evidence surfaced that they were linked to the group. Suspects were serving and former military officers and 12 former cadets who were expelled from a military school on suspicion of their links to FETÖ, in the wake of the July 15, 2016 coup attempt carried out by the group’s infiltrators in the army. Suspects were captured by police in operations in Izmir and 12 other cities. They were identified through testimonies of other FETÖ members captured in earlier operations and through their contacts with FETÖ’s "civilian" members through pay phones, a method commonly employed by the terrorist group to ensure secrecy. The identity of some suspects was discovered in earlier investigations on an infiltration scheme by the terrorist group, to military schools. Investigations have found that would-be cadets were assigned special codes that could be recognized by FETÖ-affiliated military officers interviewing them for admission to military school, thus, links between admission officers and cadets would not be easily detected.

In the capital of Ankara, the Chief Prosecutor’s Office ordered the detention of five suspects who were users of Bylock, an encrypted messaging app developed and exclusively used by members of the terrorist group. Operations were underway to capture the suspects.

ByLock was discovered during criminal inquiries into the terrorist group, whose illegal activities have been under the spotlight since two coup attempts in 2013. The National Intelligence Organization (MIT) uncovered the messaging app was apparently programmed or modified for the exclusive use of the group's members. A group of intelligence officers has been accused of controlling the private app used to deliver FETÖ leader Fethullah Gülen's messages to his followers, as well as to instruct the group's members on how to carry out plots against the group’s "foes." The ByLock investigation was expanded after the 2016 coup attempt, and thousands of people accused of using the messaging app to communicate Gülen's messages to subordinates or for pro-terrorism propaganda have been detained or arrested.

Servers of the app deployed in Lithuania were brought to Türkiye where MIT teams work to decode them. Prosecutors have launched investigations into thousands of suspects, ranging from shopkeepers to high-ranking generals and bureaucrats, housewives and prominent businesspeople detained for exchanging messages via ByLock for acts of terror. Most of the defendants claim they "accidentally" downloaded the app and never used it, while others claim they did not use it for FETÖ-related purposes. However, the messages, including those urging FETÖ members to help the coup plotters, show that the app was one of the secretive group's most-employed means of communication. Other encrypted messaging apps were later used by FETÖ members after the authorities discovered ByLock.

The operations are held on the 12th anniversary of FETÖ’s infamous plot against MIT. Known as the "February 7 Conspiracy," the plot aimed for the detention of then-MIT Director Hakan Fidan, who currently serves as Foreign Minister. FETÖ-linked prosecutors were accused of attempting to detain him based on false evidence. A lawsuit was filed against several suspects, including FETÖ’s "handlers" for their infiltrators in law enforcement and former police chiefs. Fifteen suspects were sentenced in the trial for their role in the plot. An indictment against the defendants said that FETÖ sought to implicate MIT officials on trumped-up charges of links to the terrorist group PKK. Fidan and other officials were summoned by FETÖ-linked prosecutors in 2012 but then-Prime Minister Recep Tayyip Erdoğan ordered Fidan and others to disobey the summoning orders. Subsequent investigations showed that although prosecutors claimed just to obtain a statement from Fidan, their true goal was to have Fidan arrested inside the courthouse.