Two 15-year-old students were hospitalized and a 12-year-old student was taken into custody after shots were fired inside a middle school classroom Thursday morning at a campus northwest of downtown Los Angeles.

Police responded to the report of shots fired at the campus of Belmont High School and Sal Castro Middle School, located in Los Angeles’ Westlake District.

The victims, a boy and girl, are both 15 years old, police said. The boy was hospitalized in critical condition with a gunshot wound to the head, fire officials said. His condition was later upgraded to serious, but stable.

The girl was in fair condition with a gunshot wound to the wrist, according to the fire department.

It was not immediately clear how many students were in the classroom at the time of the shooting. Some students ran from the classroom as the gunfire started, police said.

Aerial video showed officers escorting a female student in handcuffs from the campus, but authorities did not immediately confirm she was the 12-year-old individual detained as the shooting suspect. Authorities also recovered the weapon used in the shooting.

Three other individuals suffered non-gunshot injuries, such as minor scrapes.

Sal Castro Middle School is on the Belmont High School campus, located in one of Los Angeles’ most densely populated communities. About 365 students attend grades 6-8 on the campus