YAKIMA, Wash. (AP) — At least 21 people have been arrested in a series of immigration raids in Yakima following a federal investigation into alleged document fraud, including counterfeit work authorization cards.

About 70 federal agents and police officers raided homes and businesses across Yakima Wednesday.

Andrew Munoz, a spokesman for Homeland Security Investigations in Seattle, a unit of U.S. Immigration and Customs Enforcement, told the Yakima Herald-Republic that more than 40 separate search and arrest warrants were served as part of the raids. Munoz said indictments stemmed from a lengthy investigation of document fraud.