CHICAGO — Standing on a street corner outside Hamline Elementary Monday afternoon, Gloria Marquez noticed the sidewalk had an unusually small number of parents for dismissal. Her 13-year-old and 9-year-old attend and are U.

Fearing federal agents asking to search a Chicago elementary school Friday morning were from Immigration and Customs Enforcement, school officials denied them entry. But it turned out they were US Secret Service agents pursuing an investigation.

The operation began at a home and later extended to the school grounds.The agency stressed that it only investigates threats, does not enforce immigration laws.