Two people were reportedly killed in the attack at North Park elementary in San Bernardino, and two students were taken to hospital.
The shooting, which happened in a classroom, appears to be a murder-suicide, Burguan tweeted. Two students were transported to a local hospital after the incident, which took place in a classroom, he said.
The situation is believed to be contained, and law enforcement officials believe the subject is down.
Law enforcement secure the scene of a mass shooting in San Bernardino, CA., on Monday.
"North Park Elementary School in the Saugus Union School District was not impacted by this unfortunate this event", Principal Sandy Brunet said. "We have a shooter down and three victims", said Maria Garcia, a spokeswoman for San Bernardino City Unified. He said the suspect is "possibly down as well".