According to reporting from Reuters, Immigration and Customs Enforcement (ICE) released a statement saying they detained 680 people who were working without documentation at different agricultural processing plants in the state of Mississippi. The agents also seized business records as part of an ongoing federal investigation.

ICE said that some of the detainees will be released for “humanitarian reasons” and will appear in US immigration court. Other detainees will be transported to an ICE facility in a different state.

ICE did not list the nationalities of the workers arrested. However, the Mexican Consulate said it was travelling to the area to assist Mexican nationals who might be involved.

Peco Foods, a large poultry producer in the United States, was among the facilities targeted in Wednesday’s operation.

Tom Super, spokesman for the National Chicken Council, an industry group, said that processing companies do their best to hire workers with the proper documentation. “The chicken industry uses every tool in the tool box to ensure a legal workforce,” he said.

Read the press release from the Southern District of Mississippi here and read the reporting from Reuters here.