Three juvenile students, one adult student and a teacher were arrested Saturday on charges relating to child endangerment.
Eyewitness News has learned that the alleged incident, which happened during summer school, was sexual in nature.
Police said the hazing involved the physical assault of at least one student, and the incident appears to have been confined to one classroom. The teacher, 27-year-old Emmanuel de la Rosa, knew the assaults were taking place and may have directed the students to assault the alleged victim due to behavioral problems, according to investigators.
"The teacher was either familiar with what was going on or maybe had actually directed the students on how to do that hazing," said Fontana police Sgt. Robert Morris.
Several students were interviewed in a Fontana Unified School District Police investigation. Fontana police were then contacted.
De la Rosa was released on bail Sunday.
The 18-year-old student was identified as Fernando Salgado. He was charged with assault, attempted sodomy and child cruelty.
Authorities said the four also assaulted three other students.
Anyone with information on the incident or other possible acts of hazing was asked to call the Fontana Police Department at (909) 935-0740.