Authorities Wednesday were investigating allegations that a third-grade boy at a Riverside elementary school sexually assaulted another boy repeatedly since last year.
The alleged abuse took place five to seven times and began when the Adams Elementary School students were in second grade, said Jacquie Paul, spokeswoman for the Riverside Unified School District.
"One of the young boys apparently was coercing another young boy to perform sexual acts," she said.
Paul declined to provide additional details, citing the age of the two children and an ongoing investigation.
Riverside police were notified Monday by the school district and have launched an investigation, Lt. Val Graham said.
Officials at the school found out about the abuse Monday evening when students at an after-school program told a staff member that "they wanted to report something they knew," Paul said.
The two students involved in the incidents were also in the after-school program and were interviewed by the principal that evening.
The school district notified parents Wednesday in a letter and will be holding a meeting at the school Thursday at 7 p.m. to answer questions.
Paul said the student suspected of the abuse has been suspended from the school and could be expelled.