“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.

LA County Sheriffs

✔@LASDHQ

#LASD Shooting at Saugus High School , Please avoid the area. Male Asian suspect black clothing last seen at the location. Deputies on scene and still responding. Avoid the area Further information to follow.

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.

Henry Mayo Hospital@HenryMayoHosp

#SaugusHighShooting: We have received 2 patients in critical condition, 3 en route. We will provide updates as they become available.

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.”