POSTVILLE, Iowa – Immigration officials raided the Agriprocessors Inc. plant in Postville on Monday as part of an investigation into identity theft.

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

Counts said all those arrested would be interviewed by ICE agents to determine if they should be detained. If someone raises questions based on humanitarian grounds, they could be released pending a detention hearing.

“Usually, it’s medical or if someone is a primary care giver to a child,” Counts said.

He also said a toll-free telephone number had been set up to assist family members of those arrested who have questions about their detention status and the removal process.

A news conference was scheduled for 2 p.m. at the U.S. attorney’s office in Cedar Rapids.

Sister Mary McCauley, a Roman Catholic nun at St. Bridget’s Catholic Church in Postville, told The Associated Press that family members of plant workers were coming to the nearby church in tears.

“The people right now are hearing and seeing the helicopters,” McCauley said. “They are just panic-stricken and very frightened and some of them are coming to the church as a safe haven.”

The church is about five blocks from the plant, she said.

She said rumors began swirling around the community on Friday about an upcoming raid, leaving many people worried.

She said immigration officials arrived with buses, vans and two helicopters.

She said she went to the plant to help provide information and assist workers but was not allowed to get close.

“Some of the people that are going to be detained are up against a fence and now they’re tying their hands,” she said.

Many of the plant workers are Hispanic, mostly from Mexico and Guatemala, she said.

Agriprocessors is the world’s largest kosher meatpacking plant.

The raid comes after immigration rights activists said they feared the National Cattle Congress fairgrounds in Waterloo may have been converted into a detention center.

Those concerns were prompted by an announcement last week that federal officials have leased the fairgrounds through May 25. The government said earlier this month that it leased the fairgrounds for a training exercise.

Doug Miller, general manager of the fairgrounds, said he was not allowed to release many details but that massive generators had been installed next to many of the buildings and windows had been covered up. A number of trailers have also been set up at the site.

Waterloo is about 75 miles from Postville.

In December 2006, ICE raided the Swift & Co. meatpacking plant in Marshalltown, arresting at least 90 workers as part of a six-state raid.

Several of the workers were taken to Camp Dodge in Johnston and held in military barracks.

About 1,280 Swift workers were arrested in the raid in Iowa and the five other states in the biggest crackdown in history on immigration violations at one company.