More than 1,200 people were arrested in meatpacking plants in six states during raids that federal officials said amounted to the largest-ever workplace crackdown on illegal immigration.

Homeland Security Secretary Michael Chertoff said Wednesday the investigation uncovered a "disturbing front" in the war against illegal immigration, in which illegal immigrants are using the identities of U.S. citizens to obtain jobs.

"Violations of our immigration laws and privacy rights often go hand in hand," he said. "Enforcement actions like this one protect the privacy rights of innocent Americans while striking a blow against illegal immigration."

The raids at Swift & Co. plants across the country resulted in 1,282 arrests, including 1,217 on immigration charges and 65 on criminal charges such as identity theft. Chertoff said the investigation is continuing into several groups that may have sold identity documents to illegal immigrants.

The arrested workers were from Mexico, Guatemala, Honduras, El Salvador, Peru, Laos, Sudan, Ethiopia and other countries.

During a raid Tuesday at the Swift plant in Greeley, Colo., a frustrated Tony Garcia watched as Immigration and Customs Enforcement agents swarmed inside to arrest illegal immigrants. "We need help, we need answers," he said, questioning who would take care of the children whose parents were arrested.

The raids followed a 10-month investigation into illegal immigrants suspected of buying or stealing other people's identities to secure U.S. jobs. The scheme may have had hundreds victims, officials said.

Immigration officials last month informed Swift that it would remove unauthorized workers on Dec. 4, but Swift asked a federal judge to prevent agents from conducting the raid, arguing it would cause "substantial and irreparable injury" to its business.

The company estimated a raid would remove up to 40 percent of its 13,000 workers. Greeley-based Swift describes itself as the world's second-largest meat processor with sales of about $9 billion.

After a closed hearing, a judge on Thursday rejected Swift's request, clearing the way for Tuesday's raids at the plants in Greeley; Grand Island; Cactus, Texas; Hyrum, Utah; Marshalltown, Iowa; and Worthington, Minn.

The six plants represent all of Swift's domestic beef processing capacity and 77 percent of its pork processing capacity.

Advocates of stricter immigration control praised the raids and pointed out that they targeted people suspected of committing other crimes in addition to being in the U.S. illegally.

"I'm glad that ICE is enforcing our immigration laws in light of the illegal immigration crisis we face across the country," Sen. Wayne Allard, R-Colo., said in a statement.

Others called the raids heavy-handed and criticized the effect on families.

"They are taking mothers and fathers, and we're really concerned about the children," said the Rev. Clarence Sandoval of St. Thomas Aquinas Roman Catholic Church in Logan, Utah. "I'm getting calls from mothers saying they don't know where their husband was taken."

United Food and Commercial International Workers union spokeswoman Jill Cashen told the Post workers taken from the Worthington, Minn., plant were bused to South Dakota.

She said Tuesday that attorneys for the union would ask federal judges in all six states for injunctions to halt the raids.

Mexico's Foreign Relations Department also pledged to ensure that any Mexicans caught up in the raids have "their human rights fully respected, and are given all the necessary assistance, orientation and consular protection."

No charges were filed against Swift.

In a written statement, President and CEO Sam Rovit said the company has never knowingly hired illegal workers and does not condone the practice.

Swift uses a government pilot program to confirm whether Social Security numbers are valid. Company officials have raised questions about the program's ability to detect when two people are using the same number.

Immigration agents have also staged immigration raids at poultry plants in the South. In July 2005, nearly 120 people were arrested at an Arkadelphia, Ark., facility. Three months ago, agents raided a poultry plant in Stillmore, Ga., arresting a similar number who worked there or lived in surrounding counties and busing them to immigration courts in Atlanta, 189 miles away.