WATERLOO - The immigration raid on a Postville packing plant ranks as the largest ever targeting a single site.

Around 390 people were arrested Monday as U.S. Immigration and Customs Enforcement agents descended on Agriprocessors, the nation's largest kosher packing plant.

"We're here to discuss not only the largest operation of its kind ever in Iowa, but in fact, the largest single-site enforcement operation of its kind in the country, based on those numbers and those people administratively arrested," said U.S. Attorney Matthew M. Dummermuth during a press conference in Cedar Rapids.

As of Tuesday night, 10 males and 10 females faced criminal charges, ranging from aggravated identity theft to fraudulent use of a Social Security number. The number of people facing criminal charges could increase, officials said.

Of those arrested, 314 were male and 76 were female. Twelve juveniles at the plant were detained, said Claude Arnold, special agent in charge of the ICE office of investigations in Bloomington, Minn.

The majority of the people - 290 - came from Guatemala, he said. About 93 were Mexican. Two were Israeli and the rest were Ukrainian.

Fifty-six people were released on humanitarian grounds, either for health conditions or because children would be left without parents.

Most of those released were women. Arnold said ICE has been trying to take such concerns into account throughout the intake process.

The approximately 20 to 30 remaining women were being held in the Hardin County Jail, he said. Arnold said processing of arrestees should be finished today.

"We don't expect anyone will be detained at large at the fairgrounds past Wednesday night," he said.

Arrestees face two different paths.

Persons facing criminal charges will be remanded to U.S. Marshals after an initial appearance before a magistrate.

If there are no criminal charges, arrestees remain in ICE custody to undergo removal proceedings, Arnold said.

ICE agents arrested 361 people on criminal charges in a similar raid in New Bedford, Mass., last year. Most of those arrestees faced deportation.

At a press conference Tuesday, ICE officials showed a video of the processing area, which included enough space for nearly 700 people. The area included showers, sleeping arrangements and entertainment.

"You can see this was not just a small operation," said Bob Teig, an assistant U.S. attorney.

An immigration attorney was allowed access to the National Cattle Congress grounds Tuesday, but several others say they were denied access.

Efforts to arrange legal aid and bring families staying in a Catholic church in Postville closer to detained family members were under way this morning at El Centro Latinoamericano.

The Guatemalan consulate in Chicago said this morning it was sending two representatives to Iowa. The Latino resource center is coordinating with area churches and St. Bridget's Catholic Church in Postville to transport people to shelters in Waterloo to be near detained family members.

Contact Josh Nelson at (319) 291-1565 or josh.nelson@wcfcourier.com.