LOS ANGELES- Two 15-year-old students were shot Thursday morning in a classroom at Sal Castro Middle School in Los Angeles, and a 12-year-old female student is in custody as a suspect, officials said.
One boy was shot in the head and is in critical condition, and a girl was shot in the wrist at the school, which shares a campus with Belmont High School, Los Angeles fire Capt. Eric Scott said.
Three others -- a woman and two children -- were being treated for minor cuts, including some from glass, Scott said.
"Our campus, while it's on lockdown, is safe. There is no more safety threat to the students of this school," city schools Police Chief Steven Zipperman said late Thursday morning.
The shooting was reported to Los Angeles police at 8:55 a.m. Police found and confiscated a gun at the scene, Los Angeles police Lt. Chris Ramirez said.
Police didn't say what led to the shooting, and little information was immediately released about the girl who was detained. Zipperman said she was 12.
The motive is under investigation, Ramirez said. Ramirez and Los Angeles police spokesman Drake Madison both said the girl in custody is a suspect.
Aerial video from CNN affiliates showed police appearing to search students outside the building.
The school day will continue, and students will have the chance to talk to counselors about the shooting, said Vivian Ekchian, interim superintendent of the Los Angeles Unified School District.
"The school has been declared safe, and we are communicating with parents of students at Castro Middle School, as well as neighboring campuses," she added.
Sal Castro Middle School is near the city's Westlake district, roughly a couple of miles northwest of downtown.
Third school shooting in recent weeks
This is at least the third US school shooting in recent weeks.
On January 23, a student is accused of shooting 16 people -- killing two -- at western Kentucky's Marshall County High School in Benton.
The day before, a 15-year-old student was injured in a shooting in the Texas city of Italy. A suspect, a 16-year-old male, was "apprehended within minutes," city officials said.