Oregon ? Federal agents on Tuesday raided the offices of a Portland food processing plant suspected of employing hundreds of illegal workers who used Social Security numbers that belonged to other people or were made up.

More than 165 plant workers were detained to be processed for possible deportation, officials said, and three people were indicted on immigration, illegal documents and identity theft charges.

The raid at American Staffing Resources Inc. offices at a Fresh Del Monte Produce fruit and vegetable processing plant was based on an investigation by Immigration and Customs Enforcement and the Social Security Administration that began in January, officials said.

Separate American Staffing offices also were searched, along with a Fresh Del Monte office, officials said.

The detained workers were being processed in Washington state, pending an appearance before an immigration judge. More than 30, however, were released because of humanitarian concerns but given a notice to appear, officials said.