Immigrants in large cities have been preparing for mass arrests since Trump won election in November, but reports that his initial push would be in the Chicago area has brought a new sense of urgency and fear.

“They feel they have been targeted for who they are. They feel like they’re reviving this fear they had eight years ago,” said Sanchez of St. Rita of Cascia Parish on Chicago’s South Side. “They’re feeling like something is going to happen. This is not their city because of the threat.”

Sanchez, whose congregation has consisted mostly of people of Mexican descent since the 1980s, devoted Sunday Mass “to solidarity with our immigrant brothers and sisters.”

Some immigrants in the country without legal status have been designating power of attorney to trusted friends, making plans for childcare in case of separations and installing security cameras on their doors in case immigration agents come. Others have left voluntarily, as Trump aides have encouraged them to do.

Plans for deportation arrests are in flux, but federal immigration officers will target more than 300 people with histories of egregious, violent crimes after Trump takes office Monday, one official said Saturday, speaking on condition of anonymity because the plans have not been made public.

The operation will be concentrated in the Chicago area and continue all week, subject to potential weather delays, the official said. Temperatures in Chicago dipped to 6 degrees Fahrenheit (-14.4 degrees Celsius) with cold temperatures forecast throughout the week.

U.S. Immigration and Customs Enforcement arrests a fraction of its targets in such operations, though Trump is expected to cast a wider net than President Joe Biden, whose focus on picking up people away from the border was largely limited to those with serious criminal histories or who pose a risk to national security. Biden’s administration also ended the practice of mass worksite arrests, which were common under Trump, including a 2019 operation targeting Mississippi chicken plants.

Trump aides have said they will arrest others, such as spouses or roommates, who are not targets but happen to be in the country illegally.

Trump told NBC News on Saturday that mass deportations remain a top priority. He didn’t give an exact date or city where they’ll start, but he said they would begin soon.

“It’ll begin very early, very quickly,” he said, adding: “I can’t say which cities because things are evolving. And I don’t think we want to say what city. You’ll see it firsthand.”

Sanctuary cities, which limit how local police can cooperate with federal immigration agents, have been one of Trump’s favorite targets — especially Chicago.

The nation’s third-largest city became a so-called sanctuary city in the 1980s and has beefed up its policies multiple times since, including after Trump first took office in 2017. Last week, the City Council heartily rejected a longshot plan calling for exceptions allowing local police to work with ICE agents on deportation cases for people accused or convicted of crimes.

Trump’s incoming so-called “border czar” Tom Homan blasted top Democratic leaders in the state during a visit to the Chicago area last month where he indicated enforcement would start there. But in recent days he told media outlets that plans were evolving.

Homan said on the Fox News program “America’s Newsroom” on Sunday that Chicago was still on the table but that the new administration was “reconsidering when and how we do it.”

An ICE spokesperson referred questions Sunday to the Trump transition team, which did not immediately respond to a request for comment. The plan was reported earlier by The Wall Street Journal, which said the operation is expected to begin Tuesday.

Community and religious leaders in Chicago said they were disappointed with the potential operation, but ready.

Chicago Mayor Brandon Johnson said Sunday on X that his “commitment to protecting and supporting this city remains unwavering.”

Cardinal Blase Cupich, who leads the Archdiocese of Chicago, spoke out as well.

“The reports being circulated of planned mass deportations targeting the Chicago area are not only profoundly disturbing but also wound us deeply,” Cupich said Sunday during a visit to Mexico City, according to a copy of his prepared remarks. “We are proud of our legacy of immigration that continues in our day to renew the city we love.”

Immigrant rights advocates in Chicago rallied Saturday, including Democratic U.S. Reps. Jesus “Chuy” Garcia and Delia Ramirez. They urged immigrants in Chicago to remain calm and exercise their rights, particularly to remain silent and refuse to allow officers into their homes without warrants. Some advocacy groups have planned legal workshops anticipating mass arrests next week.

Ramirez planned to skip Monday’s inauguration to post flyers in immigrant-heavy Chicago neighborhoods with information on what to do in case of an encounter with immigration agents.

“We won’t let our guard down in Chicago,” Garcia wrote on X.

Carlos, an immigrant from Mexico, has lived in the Chicago area for decades. The 56-year-old doesn’t have legal status to stay in the country but has work authorization in construction and welding. He declined to give his last name and discuss details of his immigration status for fear of being targeted for deportation.

He has three children who have legal status to stay in the country through the Obama-era Deferred Action for Childhood Arrivals, or DACA, which remains in legal limbo.

Carlos said the family’s contingency planning for deportation includes finding someone to manage their bank accounts, home and car. They’ve also installed a camera on their suburban Chicago home and plan to screen all visitors.

“If people come to the house, don’t open the door,” he explained. “Ask who it is. Don’t open it unless they have an order.”