In what’s being called the largest immigration raid in Iowa history, agents today raided the Agriprocessors Inc. meat processing plant in tiny Postville, arresting as many as 300 people.

Agents with U.S. Immigration and Customs Enforcement entered the plant at about 10 a.m. looking for evidence of identity theft, use of stolen Social Security numbers and for people who are in the country illegally, Tim Counts, an ICE spokesman told the Waterloo/Cedar Falls Courier.

The raid at Agriprocessors Inc. – considered to be the world’s largest kosher meatpacking plant with more than 1,000 workers -- came after months of planning and is likely to stoke the national debate on what to do with illegal aliens now in the country.

Detainees rounded up today are being taken to the Waterloo, Iowa, National Cattle Congress grounds, a venue more accustom to holding livestock than people.

Male detainees will be held at the fairground's intake center in northern Iowa until at least Thursday, officials said.  Female detainees are to be housed in local jails.

Those arrested will face criminal and civil charges including identity theft, improper use of Social Security data and other crimes.

“ICE is committed to enforcing the nation’s immigration laws in the workplace to maintain the integrity of the immigration system,” Claude Arnold, a special agent in charge of the ICE Office of Investigations based in Bloomington, Minn., said in a statement.

The U.S. District Court for the Northern District of Iowa will be temporarily relocated to Waterloo in anticipation of arrests, according to a release from the court.

Video shot by the newspaper showed a flurry of activity on the cattle congress grounds. Just past noon, a Homeland Security helicopter landed on the grounds and buses were there and at the meatpacking plant.

Earlier this month, federal officials set up dozens of trailers, generators and other equipment at the grounds, sparking fears in Waterloo and Northeast Iowa an immigration raid was in the works.

Cattle Congress officials said last week they were told the space was rented for a training exercise, the paper reported.

Feelings of unease have spread beyond Latino communities in Northeast Iowa because federal officials have been so tight-lipped about their intentions, the paper reported.