ISTANBUL (Reuters) - Turkish police detained 65 suspects on Thursday in an operation targeting air force personnel accused of links to the U.S.-based preacher whom Ankara says orchestrated an attempted coup in 2016, state-run Anadolu news agency said.

Prosecutors issued arrest warrants for a total 96 people, of which 91 were from the air force, and police were still seeking the remaining suspects in an operation focused on the western city of Izmir and spread across 15 provinces, it said.

The suspects were said to have ties to the cleric Fethullah Gulen, whose network is accused of being behind the failed putsch in July 2016, during which 250 people were killed. Gulen has denied involvement.

In a separate operation, an Ankara prosecutor on Thursday issued detention warrants for 93 employees of a private tutoring center that was previously closed down on suspicion of links to Gulen’s network, Anadolu said.

Turkish authorities have detained 160,000 people and dismissed nearly the same number of civil servants since the failed military intervention, the U.N. human rights office said in March.

Among those detained, more than 50,000 have been formally charged and kept in jail during their trials.

Turkey’s Western allies have criticized the crackdown. Critics of President Tayyip Erdogan accuse him of using the failed putsch as a pretext to quash dissent. Turkey says the measures are necessary to combat threats to national security.