ISTANBUL (Reuters) - Turkish prosecutors ordered the detention of 103 soldiers with suspected links to the U.S.-based Muslim cleric accused of orchestrating a failed coup in mid-2016, state-owned Anadolu news agency said on Friday.

Police have carried out regular sweeps against alleged supporters of the preacher Fethullah Gulen since the coup attempt of July 2016, in which 250 people were killed. Gulen denies involvement.

In the latest operation, in Istanbul and 31 other provinces, police have so far detained 74 people, Anadolu said.

The 103 suspects, all on active service, include colonels and lieutenant colonels, it said, adding that an investigation had shown they had communicated over fixed-line and pay telephones.

Authorities say members of the alleged Gulen network communicated via payphones.

Turkey’s Western allies have criticized the crackdown, which mostly took place under a state of emergency declared shortly after the coup attempt and remained in effect until July 2018.

Erdogan’s critics 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.