the Istanbul Public Prosecutor’s Office has issued detention warrants for at least 77 people on accusations that they use a smart phone application known as ByLock, the state-run Anadolu news agency reported on Tuesday.

According to the report, police have so far detained 14 of the suspects in simultaneous operations in İstanbul and Muğla provinces.

Turkish authorities believe that ByLock is a communication tool among members of Turkey’s Gülen group, which the Turkish government accuses of masterminding a coup attemot on July 15, 2016.

The group denies any involvement.

Tens of thousands of people, including civil servants, police officers, soldiers, businessmen and homemakers, have either been dismissed or arrested for using ByLock since the failed coup attempt.

The Supreme Court of Appeals’ Assembly of Criminal Chambers ruled last month that the ByLock smart phone application is to be considered evidence of membership in a terrorist organization following Turkish Justice Minister Abdülhamit Gül’s remarks on ByLock constituting strong evidence of terrorist organization membership.

The Guardian last month reported on a study commissioned by opponents of Turkish President Recep Tayyip Erdogan which argues that the arrest of 75,000 suspects primarily because they downloaded the ByLock app was arbitrary and illegal.

“The evidence that the [ByLock] app was used exclusively by those who were members or supporters of the Gülen movement [is] utterly unconvincing and unsupported by any evidence,” the two barristers conducting the study said, according to the Guardian.”