An elementary school on Chicago's Northwest Side was placed on lockdown Monday afternoon after an employee made a threat against the school, according to police.

Chicago police confirmed Ebinger Elementary School was on lockdown after two employees became involved in a verbal altercation and one threatened to come back and "shoot the school up."

Students, faculty and parents were escorted out of the building by Chicago police officers.

The school could not immediately be reached for comment.

No one was in custody as of early Monday evening, but police said an investigation remained ongoing.

Check back for details on this developing story.