Eric Phillips tweeted: "Mayor's been briefed on a federal immigration agent showing up at Queens' PS 58 Thursday asking about a 4th grader. School turned him away."
Phillips says the agent had no warrant.
The city's Immigration Affairs Office later tweeted that all students, regardless of status, are welcome in city schools, but federal immigration enforcement is not.
The New York City Department of Education released a statement Saturday night saying,
"All students, regardless of immigration status, are welcome in NYC public schools, and parents should rest assured that we will do everything on our power to protect students, staff and families. The federal agent was turned away -- we're looking into this incident and are providing schools with additional information on our protocol and more trainings."