Authorities issued arrest warrants for 36 suspects, mostly former and current personnel of the Turkish Armed Forces (TSK), on Wednesday on charges of links to the Gülenist Terror Group (FETÖ). Twenty-one suspects were captured in operations in 10 cities while a search is underway for others.

Arrests are the culmination of an investigation based in Istanbul focused on the secret military network of the terrorist group, which carried out a putsch attempt six years ago through its infiltrators in TSK.

Wanted and captured suspects include a former colonel and officers of lower ranks, as well as 20 former military cadets. Some suspects were on active duty, while others were expelled from the army in earlier investigations on suspicion of links to FETÖ. All were or have been members of different army branches, from Gendarmerie General Command to Air Forces, Land Forces and Naval Forces.

Suspects were identified through a far-reaching investigation into the contacts of FETÖ’s "handlers" for army infiltrators with the latter through public payphones. Public payphones were found to be the most common method among handlers and infiltrators, as previous investigations of the group eager to cover its tracks showed. Some suspects were identified through their links to suspects arrested in earlier investigations that collaborated with authorities.

Also on Wednesday, a court in the northwestern province of Edirne ordered the arrest of four FETÖ suspects who were caught while trying to cross into Greece through this border province. The suspects were caught in a military zone trying to cross the border on Tuesday.

Greece is the main gateway to Europe for FETÖ members and was also criticized by Ankara in the past for refusing to extradite military officers involved in the 2016 coup attempt.

Most military officers involved in the coup attempt were tried and sentenced since the attempt, but on Wednesday, a court in the capital Ankara ruled for the acquittal of Yıldırım Güvenç, a general who was earlier accused of links to FETÖ. Güvenç was among seven defendants on trial over the coup attempt. He and three others, including a brigadier general, were acquitted, while three defendants were sentenced over "membership of a terrorist organization" with prison terms between six and seven years.

Güvenç was serving as commander of the logistics department of Land Forces Command when the 2016 coup was attempted. He was detained a few days after the coup bid was quelled when his name was discovered in the list of commanders putschists sought to install to rule the country once the coup succeeded. Güvenç would reportedly have controlled public broadcaster TRT in post-coup Turkey. Güvenç pleaded not guilty to the charges and insisted he fought against the coup attempt as one of the few high-ranking commanders in the capital Ankara during the bid when putschists held top military brass hostage. He was released with judiciary control in 2019.