Twenty-eight military officers were detained on Monday as part of ongoing operations targeting the followers of the Gülen movement due to their use of a smart phone application known as ByLock.

The operations, which were based in the western province of Balıkesir, were conducted across 12 provinces.

Turkish authorities believe ByLock is a communication tool between members of the Gülen movement.

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

Turkey experienced a military coup attempt on July 15 that killed over 240 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 movement.

The Gülen movement strongly denies having any role in the putsch.

Over 135,000 people, including thousands within the military, have been purged due to their real or alleged connection to the Gülen movement since the coup attempt, according to a statement by the labor minister on Jan. 10. As of Feb. 1, 89,775 people were being held without charge, with an additional 43,885 in pre-trial detention due to their alleged links to the movement.

This article originally appeared in Turkish Minute on Feb. 6.