Updated

Prompted by concern's over President Trump's immigration crackdown, Chicago public schools on Tuesday told principals to refuse entry to any immigration officer without a warrant at their school, according to the Chicago Tribune.

Nearly half of Chicago’s 381,000 students are Hispanic and concerns have risen about the possibility of authorities detaining parents outside schools and their children inside.

"To be very clear, CPS does not provide assistance to U.S. Immigration and Customs Enforcement (ICE) in the enforcement of federal civil immigration law," the message to principals said.

Homeland Security announced plans to hire thousands of immigration officials and border patrol officers and focus on illegal immigrants who have committed a crime or have criminal charges pending.

A district spokesman told the Chicago Tribune that the third-largest school system in the U.S. is not aware of any efforts from ICE officials to enter school buildings.

It remains unknown how much interest U.S. Immigration and Customs Enforcement will show in schools under Trump. There is little schools can do to thwart agents who show up with warrants, but they are acting at least in part to ease concerns of skittish immigrant communities.

The latest Trump administration guidance leaves in place Obama-era policies limiting enforcement actions at "sensitive locations," including schools. While those policies say agents should generally avoid apprehending anyone inside those designated areas, they do not stop agents from obtaining records or serving subpoenas.

Principals around the country have been stepping up efforts to make students feel supported, said JoAnn Bartoletti, executive director of the National Association of Secondary School Principals.

In Syracuse, New York, the school board approved a policy this month requiring schools to deny access to ICE officials until they consult with the superintendent. In Salt Lake City, Utah, on Tuesday the school district discussed a resolution. Connecticut's governor on Wednesday advised school districts in that state to refer any ICE agents to the superintendent. And in New York City, principals there have been told that immigration officers many not be granted access without legal authority.

Some experts say it's unlikely administrators will be tested.

Mark Krikorian, executive director of the Center for Immigration Studies in Washington, D.C., which supports tighter immigration policies, said schools do not seem to have reason for alarm and Chicago Public Schools and others implementing similar policies mostly appear to be "showing off."

Among those prioritized for arrest under the new guidelines are immigrants who abuse public benefits, which Krikorian said could include free and reduced school lunches.

"It could well affect them, but again that has nothing to do with the school grounds," he said. "It's not like ICE goes in there and says, 'Drop that tater tot, kid.'"

The Associated Press contributed to this report.