At least two students are dead and three others injured after a classmate opened fire at a high school in Southern California on Thursday morning.

Nathaniel Berhow, 16, has been identified as the suspect in the deadly shooting at Saugus High School in Santa Clarita, about 40 miles from Los Angeles.

The 16-year-old male suspect was taken into custody and was last reported to be at a local hospital in 'grave condition' from a self-inflicted gunshot wound, authorities said.

Detectives reviewed video from the scene which showed the gunman in the quad of Saugus High School in Santa Clarita when he took a gun from his backpack, shot five people and then shot himself in the head, authorities said, noting that the shooting lasted for about 16 seconds.

Authorities said there was no evidence to suggest the suspect acted on behalf of a group or with any co-conspirators. The early-morning school shooting was on the suspect's birthday, authorities said.