With two top Trump administration officials in Chicago, federal law enforcement began a “targeted” immigration blitz Sunday, according to a spokesman for U.S. Immigration and Customs

The update comes hours after Mayor Brandon Johnson, along with the mayors of Boston, Denver and New York, were sent letters asking to testify before a Congressional committee on the city's "sanctuary city" policies.

ICE has take a spotlight role in the wake of plans in Trump's administration for mass deportations. Here's what you need to know about the agency.