The Los Angeles police have taken a 12-year-old girl into custody after a shooting in a middle school on Thursday morning left five people injured, the Los Angeles Police Department said.

It is so far unclear what the motive was. The police have recovered the weapon and are questioning the student, The Los Angeles Times reported.

Among the injured are a 15-year-old boy, who was shot in the head. Doctors said the bullet did not cause much harm and the boy is in a stable condition. A 15-year-old girl was shot in the wrist, and is also recovering, CNN reported.

Two other students aged 11 and 12, and a 30-year-old woman suffered a minor wounds in the chaos after the shooting, the police said.

More than 360 students study in the Salvador B Castro Middle School, where the shooting took place, Fox News reported.

Los Angeles police spokesperson Tony Im said the police do not believe the shooting was an accident. “I don’t think you can fire that many rounds and have it be an accident,” he told CNN.

“We do not know yet how a young person ended up having the ability to have access to a firearm and bring it on campus,” Steve Zipperman, chief of the Los Angeles Unified School District police force, said, according to Fox News.