MADISON, Wis. (AP) — Federal authorities have arrested nearly three dozen people in Wisconsin as part of a multi-state sweep targeting immigrants living illegally in the U.S. previously convicted of crimes and other immigration violators.

U.S. Immigration and Customs Enforcement issued a news release Friday saying the operation began May 9 and wrapped up Monday. It covered Illinois, Indiana, Wisconsin, Kentucky, Kansas and Missouri.

Authorities arrested 331 people across the six states, including 39 in Wisconsin. Thirty-seven are from Mexico, one is from Cuba and one is from El Salvador. A dozen were arrested in Green Bay, five in Milwaukee and five in Sturgeon Bay. Arrests took place in 15 other cities, including Beloit, Janesville, Madison, Sheboygan and Waunakee.