Chicago Public Schools officials claimed Friday that federal agents from U.S. Immigration and Customs Enforcement showed up at an elementary school in the city’s South Side but were blocked by staff from entering.

The account, which triggered alarms and reports of parents and grandparents pulling their children from school, was quickly challenged by ICE spokesman David Yost, who denied the incident ever took place. Instead, it turns out, it was the U.S. Secret Service that had dispatched agents to the school while conducting a “protective intelligence investigation.”