It was a chaotic scene in Chicago's South Loop on Wednesday, as U.S. Immigration and Customs Enforcement agents and other officers took several people into custody.

Immigration advocates and several alderpersons gathered outside the building as the arrests were in progress. They say federal agents detained at least 10 people who had shown up for a routine immigration appointment.

Witnesses and an immigration advocate said about a dozen people were detained by apparent ICE agents after they were told to attend routine immigration appointments.