Multiple people were injured, at least two of them critically, in a shooting at a Southern California high school on Thursday morning, officials said.

About an hour and a half after the shooting was reported at about 8 a.m. at Saugus High School in Santa Clarita, sources said the suspect was dead from a self-inflicted gunshot wound.

The Los Angeles County sheriff's department earlier said the suspect was an Asian male wearing black clothing who was last seen at the high school.

"This is an active shooter situation," said a tweet from the Santa Clarita Valley sheriff's office before the suspect was located. "If you live in neighborhoods anywhere near Saugus High, PLEASE LOCK DOORS and stay inside. If you see suspect, male dark clothing, in backyards, etc. CALL 911."

"Parents, deputies are on scene everywhere protecting your children," said a tweet from the sheriff's office.

Henry Mayo Newhall Hospital tweeted that it has received two patients in critical condition and that other patients were en route to the hospital.

© KNBC Saugus High School

The Santa Clarita Valley sheriff's office tweeted just before 8 a.m. local time to avoid the area of Saugus High School, which is in the county of Los Angeles about 40 miles north of the city of Los Angeles. Minutes later, the office said people were reporting that shots had been fired at the school.

Saugus was placed on lockdown as were neighboring elementary schools and all of the schools in the William S. Hart Union High School District, officials said.

Aerial video showed students with their hands raised, being escorted by deputies away from the school of about 2,300 students, NBC Los Angeles reported. They were transported from the campus on school buses with armed deputies on board.

An area was set up for parents to reunify with students at a park about three miles from the school.

White House spokesman Judd Deere told The Associated Press that President Donald Trump is monitoring reports on the incident.

This is a developing story; please check back for updates.