A female student was dead and several other people were injured Thursday when a 15-year-old suspect — who's now in custody — opened fire at Saugus High School in California, officials said.

"Suspect is in custody and being treated at a local hospital," Los Angeles County Sheriff Alex Villanueva tweeted.

The shooter had been described as a "male Asian suspect" wearing black clothing who was last seen walking away from the scene, the sheriff's office said. He was believed to be a student at the school, KNBC reported.

Two male patients were in critical condition at Henry Mayo Hospital, with another male patient in good condition, the medical center tweeted. It wasn't immediately clear if there were other injuries — either as the result of the gunfire or sustained in the aftermath — as the number of total injuries fluctuated between three and seven in numerous reports throughout the morning. Authorities had also said one person required CPR at the scene.

A weapon was recovered at the scene, according to an update from the William S. Hart Union High School District, where all school lockdowns were lifted as of 1:40 p.m. ET. The school district also confirmed that there is only one suspect.

It was not immediately clear if the shooting occurred inside the school building, on school grounds or near the school. It also wasn't clear what time the shooting happened, but a lieutenant with the fire department told Fox News school began at 6:55 a.m.

"Deputies on scene and still responding," the department tweeted. "Avoid the area Further information to follow."

President Trump "is monitoring the ongoing reports of a school shooting in Santa Clarita, CA," the White House said in a statement. "The White House encourages all those in the area to follow the advice of local law enforcement and first responders."

Saugus High School is located 40 miles northwest of Los Angeles. Several students were transported out of the school on gurneys, and at least one person was discovered wounded inside of the school's choir room, the Los Angeles Times reported. Read more at FOX News