A 12th Venice High School student sought in connection with an ongoing sex crimes investigation surrendered Tuesday, authorities said.
The student turned himself over to officers at the Los Angeles Police Department's Pacific Station early Tuesday morning.
Police said they are continuing to search for two other students.
Detectives are investigating a series of alleged sex crimes that they said began more than a year ago and involved two female students.
Officers arrested 10 Venice High students Friday on and off campus after the allegations came to light, and now have arrested two more this week. Police said the charges include sexual assault and lewd acts with a minor.
The arrests came after detectives were tipped off by school officials regarding a possible sexual assault.
Police have revealed little about the allegations, citing the sensitive nature of sexual crimes investigations and the juvenile status of the accused and the alleged victims.
Authorities said a group of male teenagers pressured two female classmates into numerous sex acts, some of which were coerced and others that were consensual.
Sources told The Times that several boys were present during at least some of the sex acts, and that they had threatened to harm the girls' reputations if they did not comply. The sources said some of the accused were athletes who played football and basketball at the school.
On Friday, L.A. Unified Supt. Ramon Cortines said crisis counselors were on campus to assist students.
"This is a painful moment for Venice High School and this district," he said in a statement. "I want you to know that no sexual misconduct of any kind by students or staff will ever be tolerated in L.A. Unified."
Staff writers Howard Blume and Javier Panzar contributed to this report.