Turkish prosecutors Tuesday issued arrest warrants for 137 suspects across Turkey for their alleged links to the Gülenist Terror Group (FETÖ), the group behind the 2016 defeated coup.

The Ankara Chief Public Prosecutor's Office issued arrest warrants for 50 FETÖ suspects as part of an ongoing probe into the group's infiltration into the Turkish army, said a police source, who asked not to be named due to restrictions on speaking to the media.

The arrest warrants for the Gendarmerie General Command personnel - all on-duty soldiers - were issued for allegedly having contact to the "covert imams" of FETÖ by payphone, the source added.

Meanwhile, the Chief Public Prosecutor's Office in Konya also issued 50 arrest warrants for FETÖ suspects, including 32 on-duty soldiers. Security forces launched simultaneous operations in 31 provinces to nab the suspects. Separately, the Chief Public Prosecutor's Office in Kocaeli issued warrants for 22 military personnel including 17 on-duty soldiers suspected to have links to the FETÖ. Police carried out simultaneous raids in 13 provinces to arrest the suspects.

The Chief Public Prosecutor's Office in Muğla also issued warrants for 15 FETÖ suspects - including 14 on-duty soldiers. Simultaneous operations were launched in seven provinces to nab the suspects.

FETÖ and its U.S.-based leader Fetullah Gülen orchestrated the defeated coup of July 15, 2016, which left 251 people killed and nearly 2,200 injured. The terrorist group is accused of employing its infiltrators from Air, Land, Naval and Gendarmerie forces of the Turkish Armed Forces (TSK) to overthrow the government. Their 2016 attempt failed due to a strong public resistance against the putschists and tens of thousands of people were detained or arrested in its aftermath. Operations are held almost daily to bring every FETÖ suspect to justice, although their tactics to hide their links to FETÖ prove challenging for investigators. Some suspects can only be identified through their links to the already captured FETÖ members and by "confessions" of suspects detained in earlier operations who seek a reduction in their sentence in exchange of giving information about the terrorist group.

Turkey also accuses the terrorist group of being behind a long-running campaign to overthrow the state through the infiltration of Turkish institutions, particularly the military, police, and judiciary.