Authorities Wednesday issued detention warrants for 34 former employees of public broadcaster Turkish Radio and Television Corporation (TRT) in the latest crackdown on infiltrators of the Gülenist Terror Group (FETÖ) in state-run organizations. Eight suspects were detained in Istanbul while police search for the remainder.

The suspects are accused of using ByLock, an encrypted messaging app exclusively used by FETÖ members.

TRT was the target of the putschists during the July 15 coup attempt last year. Pro-coup troops linked to FETÖ raided the Istanbul headquarters of the public broadcaster and forced presenter Tijen Karaş at gunpoint to read the declaration of the Peace At Home Council of the putsch commanders. Civilians urged by President Recep Tayyip Erdoğan to take to the streets against the putschists had stormed TRT, and pro-coup troops had to surrender shortly after a shivering Karaş recited the declaration announcing the coup.

Since the coup has been quelled, tens of thousands of suspected FETÖ members and supporters have been arrested and more than 100,000 civil servants were dismissed for possible links to the group.

Fetullah Gülen, the U.S.-based leader of FETÖ, is the prime suspect in the coup and faces life imprisonment if he is extradited, which Ankara has requested from Washington. Prosecutors say Adil Öksüz, a fugitive FETÖ member who was briefly detained when he was captured at Akıncı Air Base in Ankara, plotted the coup with FETÖ infiltrators in the Turkish Armed Forces (TSK) and executed the putsch after Gülen approved it.

A trial of 94 suspects accused of storming the TRT compound in Istanbul, as well as attempting to seize Digitürk, a major satellite provider, started in Istanbul in April. Most of the suspects are military officers of various ranks, while five of the defendants are "civilians" who helped pro-coup troops gain control of TRT or cut off its broadcast. The detained men had jumped the fence outside TRT's Istanbul headquarters minutes before anti-coup security personnel and a crowd of anti-coup civilians retook the building from pro-coup forces, as CCTV footage would later reveal. Initially thought to be civilians fleeing for their lives amidst the brutal attempt to take over TRT, the interrogators were surprised when they discovered the "civilian" detainees were former and current employees of FETÖ-linked technology companies who were brought in by troops to cut off the broadcast. Turkish media had earlier reported that an investigation was underway regarding whether some TRT employees helped the pro-coup troops.