SAN FRANCISCO (KGO) -- A published report has sparked fear in immigrant communities. The report says President Donald Trump is starting a broad crackdown on undocumented immigrants.In January of last year, ICE agents looking for an undocumented immigrant in the Mission District mistakenly visited a pre-school run by the Good Samaritan Family Resource Center . The right address was next door.Nevertheless, agents dressed for a raid, sparked fear and anger among immigration advocates."Our visit, we know was probably a means of intimidation, basically sending a message -- there's a new sheriff in town," said Executive Director of the Good Samaritan Family Resource Center Mario Paz.A report in Tuesday's San Francisco Chronicle, attributed to a source, says U.S. immigration officials are now preparing for a "major sweep" in the city and in other areas of Northern California, "in which federal officers would look to arrest more than 1,500 undocumented people."ABC7 News could not independently verify the Chronicle report.Regardless, immigrant activists tell us the story has created fear in their community."We're going to have to reach out to our community and say, send your children to school, go to work. Don't let them win," Paz added.San Francisco supervisors ABC7 News spoke with are standing together against any attack on their city's sanctuary policy.Supervisor Jeff Sheehy is an activist who was jailed twice supporting causes dear to his heart. He said he'd go to jail again on this issue. "I think we need people in office who've either been in the back of a squad car or paddy wagon, fighting for social justice and I've been in both," he said.A spokesman for ICE declined to comment on the report, saying "I am not able to speculate about future enforcement actions."