A covert law enforcement operation targeting human trafficking-related activity in Metro Detroit resulted in 21 arrests, Macomb County authorities said Friday. 

The Macomb County Sheriff's Enforcement Team (SET) led the investigation and reported on the case. That team includes detectives from the Macomb County Sheriff's Office and the Warren Police Department. Others assisting on the investigation included the Macomb County Sheriff's Office Detective Bureau, Macomb Area Computer Enforcement, Macomb Auto Theft Squad and Task Force Officers. 

Of the people who were taken into custody, 12 people face misdemeanor charges relating to commercial sex activity. The other nine face felony charges related to facilitating commercial sexual activity, authorities said. 

Those who are under investigation for felony offenses have been lodged at the Macomb County Jail; the others are released for now, pending charges. 

"Human trafficking is a serious and disturbing crime that exploits the most vulnerable among us," Macomb County Sheriff Anthony Wickersham said. "These arrests send a clear message that our office will aggressively pursue those who profit from human suffering."