Federal agents arrested more than 100 workers at an Ohio meatpacking factory on Tuesday as a part of yearlong investigation into whether the company knowingly hired undocumented immigrants.

U.S. Immigration and Customs Enforcement officials said that 146 workers were arrested at Fresh Mark’s meat processing plant in Salem, Ohio as a part of an investigation into whether the company knowingly hired illegal immigrants who used faked identities belonging to U.S. citizens to obtain employment.

Search warrants were also carried out at the company’s two other locations in Ohio.

A spokesperson for the agency, Khaalid Walls, said that the majority of the workers detained were from Guatemala.

ICE RAIDS OHIO LAWN AND GARDEN BUSINESS, ARRESTS 114

Most of those detained were released after being processed because they were either the sole care providers of children or they had health concerns.

Although Fresh Mark has not been charged, officials say the investigation is ongoing.

Tuesday’s raid is the latest attempt by the U.S. government to crack down on businesses that hire people illegally in the country.

Earlier this month, ICE agents arrested 14 suspected illegal immigrants from an Ohio lawn and garden business and in April, 225 illegal immigrants were arrested in New York raids as a part of a six-day operation.

The Associated Press contributed to this report.