U.S. Immigration and Customs Enforcement began targeted operations in Chicago on Sunday as part of a nationwide effort that federal officials said resulted in 1,000 people arrested. A spokesman Sunday declined to say how many were from the Chicago area.

Tom Homan said Chicago is very organized,” Margarita Klein, director of member organizing for Arise Chicago, proclaimed gleefully in Spanish to a room of 80 people at an immigrant rights training, many of whom laughed and clapped in response.

The campaign aims to educate residents about their rights in the event of being stopped or detained by federal agents with U.S. Immigration and Customs Enforcement, or ICE.