The incident was reported around noon at Los Angeles Academy Middle School and STEAM Magnet, near the intersection of Slauson Avenue and Avalon Boulevard.
Los Angeles police conducted a room-to-room search of the school and said no gun had been found. No shots were fired, and no injuries were reported.
Authorities said police detained one student who was accused by another student of possibly having a gun.
The school was on lockdown for hours as armed officers conducted a thorough search of the campus for any weapons, according to investigators. The all-clear was given in the late afternoon.
Parents and loved ones huddled in a staging area, eagerly waiting to pick up their children.
"I heard from my son... He was crying, yeah, he was really scared. He's still scared. Yeah, but I don't even know what's going on," parent Roberto Diaz said. He said he heard there were three fights inside the school, but no shooting.
Eyewitness News spoke to some parents who said they were alerted to the tense situation by the Nextdoor and Citizen apps, but not the school. Some said they got conflicting information from school officials about what actually happened on campus.
"The school told me that there was a big fight in the school, but that no weapon was involved... That's the reason why the school never contacted us," said Melissa, a sister of one of the middle school students.
"So do you believe that?" Eyewitness News reporter Leo Stallworth asked.
"No, because I seen the Citizen app. That's why I came over here, right away... The Citizen app said that there was a weapon involved, and when I called the school, the school said, 'Oh, there was no weapon involved,'" Melissa said.
A Los Angeles Unified School District spokesperson released the following statement:
"The safety and wellbeing of our students and staff remain my top priority. I am calling to advise you that our campus remains on lockdown due to a report received from a community member regarding a possible weapon on campus and an alleged shooting. The administrative team acted swiftly to address the matter with local law enforcement.
Please note that we have no reported injuries and no evidence of a shooting. Students and staff remain safe at this time, while law enforcement and region staff continue to respond.
We are continuing to follow District protocols, and all students and staff are safe. We will provide you with updates as they become available. Thank you."