Security forces on Tuesday detained 26 people in separate operations against the Gülenist Terror Group (FETÖ), the culprit of the July 15, 2016 coup attempt.

In one operation based in Istanbul, the Chief Prosecutor’s Office issued arrest warrants for 53 suspects, accused of taking part in the terrorist group’s secret network in the Turkish Armed Forces (TSK). Some 23 among them were detained in operations in 16 provinces, while a manhunt is underway to capture the others. Wanted and captured suspects include three noncommissioned officers from the Land Forces Command, noncommissioned officers expelled from the Air Forces Command on suspicion of links to FETÖ and former military cadets.

Suspects were identified through a string of evidence against them, including their contacts with fellow FETÖ members through public payphones, a common method employed by the secretive group, and confessions of FETÖ members arrested in earlier operations. Payphones have proven to be the terrorist group's undoing since the coup attempt was quashed. Focusing their probe on payphones in busy places, investigators managed to identify a large number of "imams" who phoned the infiltrators to arrange secret meetings.

FETÖ is still active in Turkey years after the coup attempt, in which it employed its military infiltrators. But it faces more exposure nowadays, thanks to an increasing number of members collaborating with authorities to shed light on its secretive network. In the capital Ankara alone, 1,244 people out of the 4,724 detained for links to the terrorist group collaborated with investigators last year. Their confessions, in exchange for a lenient sentence in terrorism cases against them, helped authorities to uncover nearly 20,000 FETÖ suspects previously unknown to the authorities. FETÖ members captured in operations in the years before the coup attempt were less willing to collaborate with authorities, the figures show. But this changed after the coup attempt, where several members of the group had confessed that they have seen "the true face" of the group for the first time. FETÖ, even after two coup attempts in late 2013, managed to keep its followers it exploited under the guise of a charity movement with religious undertones. Collaborators, however, draw the wrath of prominent members of the group who have fled Turkey before and after the 2016 coup attempt, and who can be deciphered on social media. Emre Uslu, a fugitive FETÖ member who currently resides in the United States, where FETÖ leader Fetullah Gülen also lives, had recently uncovered the identity of a former FETÖ member who collaborated with authorities on social media. Uslu had sought to incite fellow FETÖ members against the collaborator, "now living in Cologne, Germany."

In the northwestern province of Edirne, security forces captured three FETÖ suspects who were trying to illegally cross the border into Greece. The suspects were discovered in a military zone closed to civilian crossings in the Meriç district.

Greece has been the favorite gateway for suspects linked to the group, though most prefer land routes in Turkey's northwest. The European country attracted more FETÖ fugitives after it refused to extradite soldiers involved in the 2016 coup attempt to Turkey after they hijacked a military helicopter and took shelter in Greece.

Over 8,000 FETÖ members have crossed into Greece in the past three years, according to authorities. Ankara has criticized the country for ignoring its calls for international cooperation against the terrorist group.