LONGMONT, Colo. -- Immigration officials said they've arrested 18 people in a raid at concrete plant in Loveland.

U.S. Immigration and Customs Enforcement said the 18 workers arrested Wednesday morning were in the country illegally. One was from El Salvador and the rest were from Mexico.

ICE spokesman Carl Rusnok said the 18 will be interviewed, fingerprinted and then held at the Park County jail. He said they'll either be returned to their home country or appear before an immigration judge who will determine their fate.

ICE said Colorado Precast Concrete Inc. cooperated as agents executed a search warrant at the plant. No criminal charges are expected against the company.

In fiscal year 2008 through May, ICE made more than 850 criminal arrests tied to worksite enforcement investigations. Of the 850 individuals criminally arrested, 75 are owners, managers, supervisors or human resources employees facing charges including harboring or knowingly hiring illegal aliens. The remaining 775 workers criminally arrested are facing charges including aggravated identity theft and Social Security fraud.