LOS ANGELES -- Two 15-year-old students were shot Thursday morning at Sal Castro Middle School in Los Angeles, and a 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, 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.
"The school has been declared safe at this point. There is no more safety threat," city schools Police Chief Steven Zipperman said.
The shooting was reported to Los Angeles police at 8:55 a.m. (11:55 a.m. ET). Police found and confiscated a gun at the scene, Los Angeles police Lt. Chris Ramirez said.
It wasn't immediately clear what led to the shooting. The motive is under investigation, Ramirez said.
School police said the shots were fired in a classroom, but Ramirez later told reporters he didn't know where the shooting happened.
Aerial video from CNN affiliates showed police appearing to search students outside the building.
Sal Castro Middle School is near the city's Westlake district, roughly a couple of miles northwest of downtown, and it shares a campus with Belmont High School.
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.