A Turkish prosecutor has issued detention warrants for 38 former Customs and Trade Ministry staff members over the use of a smart phone application known as ByLock.

The detention warrants were issued as part of an investigation in nine provinces into Turkey’s Gülen group, which is accused by the Turkish government of having masterminded a failed coup attempt on July 15, 2016.

The group denies any involvement.

Turkish authorities believe using ByLock is a sign of being a Gülenist as they see the mobile phone application as the top communication tool among the group.

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

The military coup attempt on July 15 killed 249 people and wounded more than a thousand others. Immediately after the putsch, the Justice and Development Party (AKP) government along with President Recep Tayyip Erdoğan pinned the blame on the Gülen group and initiated a widespread purge aimed at cleansing sympathizers of the movement from within state institutions, dehumanizing its popular figures and putting them in custody.

Turkey’s Justice Ministry announced on July 13 that 50,510 people have been arrested and 169,013 have been the subject of legal proceedings on coup charges since the failed coup.