Istanbul prosecutor’s office on Tuesday ordered the detention of 168 people, including military personnel, with suspected links to the network that Ankara says orchestrated a 2016 coup attempt.

Turkey has cracked down on suspected followers of Fethullah Gulen, a US-based Muslim cleric, and operations against the network are still routine.

The prosecutor’s office said it ordered the detention of two civilians and 52 military personnel, including two retired colonels, a lieutenant colonel on active duty and two former majors who had already been expelled from the military. More than half of them were detained by early Tuesday, Reuters reports.

Istanbul police said they had detained 15 of the 27 people for whom the prosecutors issued warrants in a separate investigation, over the suspects’ use of ByLock, an encrypted messaging app allegedly used by Gulen’s network.