The incident that led to the arrests occurred after 11 a.m. Oct. 2 at the middle school at 23996 Eucalyptus Ave., the Riverside County Sheriff's Department said in a statement Monday.
According to investigators, Sunnymead administrators notified the school resource officer of the attack, and three students were subsequently identified as suspects.
RAW VIDEO: Cellphone videos show 2 fights at Sunnymead Middle School
"All three suspects entered the victim's classroom and assaulted both the victim and the assigned teacher," the sheriff's news release said. A bystander in the room captured the confrontation on video.
Two days later, officials said, the school resource officer unit took two of the girls into custody on multiple battery charges and booked them into Riverside County Juvenile Hall.
The third suspect is being sought. None of the students were publicly identified due to their ages.
Anyone with information about the altercation is asked to call Sgt. Tejeda at the sheriff's Moreno Valley station at (951) 486-6700.
The Oct. 2 incident came less than three weeks after cellphone video showed a fight at Moreno Valley's Landmark Middle School that left a 13-year-old boy dead.
Teen suspect in fatal Moreno Valley school fight faces judge