Federal authorities are announcing drug and firearms charges in connection with a sweep involving about 35 people in and around Lawrence, Massachusetts, on Thursday.
Thirteen undocumented immigrants with criminal histories were also arrested as a part of "Operation Law and Order," which authorities added also included arrests on state warrants.
Nine suspects who were sought in the crackdown are still at large, according to federal authorities.
U.S. Attorney Andrew Lelling said the sweep is part of the U.S. Department of Justice's "Project Safe Neighborhoods" initiative. Involving more than 200 law enforcement agents from around the region, the arrests were part of a number of federal investigations.
About 10 kilos of fentanyl, a deadly element in the country's ongoing opioid crisis, was bought or seized by law enforcement officers during the investigation, according to Lelling's office.