A former police officer who was earlier dismissed from the post over his alleged ties to the Gulen movement has been detained while visiting a hospital to see a doctor in Ankara.

State-run Anadolu news agency said Friday that the purged police officer, identified as Sadik K., was detained at Dışkapı Hospital in Ankara as he had an outstanding arrest warrant over use of ByLock mobile app.

ByLock is a smartphone application, which Turkish authorities believe is a communication tool among supporters of the Gulen movement, accused of masterminding the July 15, 2016 coup attempt. The movement denies 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 last year. Among such arrestees is Amnesty International’s Turkey bureau chief, Taner Kilic.

Hospitals, hotels as well as state institutions have become common places where suspects are required to check in for registration, involuntarily helping police to locate them.