MINNEAPOLIS (AP) — Seven men have been arrested and charged in a northern Minnesota human trafficking ring, according to state investigators.

The defendants, including five from Minnesota, were arrested Wednesday through Friday during an undercover operation. They’re being held in jails in Itasca and Pennington counties.

The Minnesota Bureau of Criminal Apprehension led the sting in partnership with the Tribes United Against Sex Trafficking Task Force and Itasca County Sheriff’s Office.

According to the BCA, the men connected with undercover investigators on sex advertisement websites. They were arrested when they showed up at arranged meetings for sex.

Many of the charges involve soliciting a person believed to be a minor.

The Minnesota defendants are from Grand Rapids, Sawyer, Chisholm and Goodridge.