No one at the scene, under a 110 Freeway overpass, required transport to a hospital, the Fire Department said.
Paramedics evaluated 39 children and five staff members who were on the bus, as well as three patients in the other vehicles, according to the LAFD. An occupant of one of the cars suffered a minor injury.
The school district that operated the bus was unknown.
The cause of the crash was under investigation.