At least 5 people were detained over their alleged use of ByLock mobile application in Turkey’s central Anatolian province of Kayseri, media reported Friday.

A Turkish prosecutor issued detention warrants for a total of 8 people in Kayseri on accusations that they use a smart phone application known as ByLock.

Turkish authorities believe that ByLock is a communication tool among followers of the Gülen movement, accused of mounting the July 15, 2016 failed coup attempt. The movement denies involvement.

Tens of thousands of people, including civil servants, police officers, soldiers, businessmen and housemakers, have either been dismissed or arrested for using ByLock since the failed coup attempt on July 15, 2016.