Four academics from the Rize-based Recep Tayyip Erdoğan University were detained in an operation on Wednesday that targeted followers of the Gülen movement for their use of a smart phone application.

The detainees include Prof. Dr. Ekrem A., the former dean of the university’s medical faculty.

The detainees are accused of using the ByLock smart phone application, which according to prosecutors, is the top communication tool among members of the Gülen movement, accused by the government of masterminding a coup attempt in Turkey on July 15.

Tens of thousands of civil servants have either been dismissed or arrested for using the application.