The victim is an African American and the assailants are white, WWNY reported.
Lauren French, the superintendent of the Gouverneur Central School District, told the television station the incident was "devastating."
"It is probably the most professionally devastating event since I started working at Gouverneur in 1984," French told WWNY.
According to police, Tiffany N. Spicer, 28, of Edwards, was the bus monitor but did nothing to prevent the attack or stop it, WTVH reported. Spicer was charged with three counts of endangering the welfare of a child, the television station reported.
The cases of the alleged attackers will be handled in family court, the television station reported.