Twenty-five suspects were detained yesterday in an investigation into Bylock, an encrypted messaging app developed and exclusively used by members of the Gülenist Terror Group (FETÖ).

The Chief Prosecutor's Office in the capital Ankara issued detention warrants for 47 suspected members of the terrorist group blamed for the July 15, 2016 coup attempt. Operations were underway to capture other suspects. All suspects are accused of using Bylock, a messaging app used to relay senior FETÖ figures' messages to other members.

Suspects include former employees of the Health Ministry, the Labor Ministry and the Education Ministry, as well as two executives of a now-defunct FETÖ-linked association and a former correspondent.

Ever since it tried to topple the government in 2016 through its military infiltrators, FETÖ has faced a heightened crackdown. Security forces nabbed more than 18,000 people in the first nine months of this year.

A total of 251 people were killed in the coup attempt that was thwarted thanks to an unprecedented public resistance. The group was already facing multiple criminal inquiries and trials when the coup attempt took place due to the group's two attempts to overthrow the government through FETÖ-linked police and judiciary in 2013.

Prior to the coup attempt, Turkish intelligence discovered that the terrorist group used Bylock and uncovered millions of messages, from simple greetings from the group's leader Fetullah Gülen to instructions on how to avoid detection.

FETÖ, which expanded its clout in Turkey over the past three decades, is known for its wide network of infiltrators in law enforcement, the military, judiciary and bureaucracy. The state of emergency declared after the coup attempt sped up the crackdown on the terrorist group's infiltrators. Tens of thousands were detained or arrested and dismissed from their jobs in the public sector after the attempt.