Authorities said the agents were initially believed to be immigration officers, prompting demonstrators to converge on the busy plaza near Imperial Highway and Long Beach Boulevard.
However, the group turned out to be uniformed TSA agents and Federal Air Marshals.
The air marshals contacted the Los Angeles County Sheriff's Department, and deputies arrived to calm the crowd and escort the group safely from the area.
The crowd dispersed shortly afterward, and no arrests were made.
No injuries were reported.