ISTANBUL — More than a thousand people, accused of being “secret imams” for an American-based cleric who the authorities have said was responsible for a failed coup in July, were detained in Turkey on Wednesday in the largest such sweep in months.

The civilian detainees are accused of directing police officers also loyal to the cleric, effectively creating a parallel leadership.

Over 9,100 police officers were suspended later in the day because of their alleged links to the movement, Anadolu Agency, a state-run news wire, reported on Wednesday night.

About 45,000 people have already been taken into custody since the coup attempt, but the raids on Wednesday represented the first widespread roundup of political opponents since a referendum on April 16 to expand the powers of President Recep Tayyip Erdogan.