(The Center Square) – A joint operation between Immigration and Customs Enforcement and FBI Milwaukee led to 21 Manitowoc County arrests of individuals in the country illegally Thursday, FBI Milwaukee said.

Nine of those arrested were suspected to be involved in “the sexual assault and/or trafficking of minor American girls,” the department posted.

“FBI Milwaukee and our law enforcement partners are dedicated to and focused on protecting and safeguarding our Wisconsin communities every day,” the department said.

Attempts by The Center Square to reach FBI Milwaukee were unsuccessful.

The arrests were done with the assistance of U.S. Marshals, the Drug Enforcement Administration, U.S. Customs and Border Protection, and the IRS Criminal Investigations unit.

The arrests are part of increased ICE arrests and immigration enforcement across the U.S.