Thousands of jailed immigrants in Chicago have vanished from federal records, human rights attorneys claim

Human-rights attorneys in Chicago say they cannot account for more than 3,000 people arrested during a federal immigration crackdown known as "Operation Midway Blitz," raising concerns about due process, transparency, and possible coerced departures.

Immigration and Border Patrol officers have arrested more than 3,000 people who authorities say were in the U.S. illegally and in some cases wanted for serious crimes, all in the seven weeks since feds intensified their efforts in the state.

Attorneys consulted by NBC Chicago, however, say federal authorities have refused — or are unable — to disclose where many of those detainees are being held or whether they have already been deported.