Three people, including a teacher and an 8-year-old student, were killed in an apparent murder-suicide at a San Bernardino, California, elementary school on Monday.

The suspected gunman was identified as 53-year-old Riverside resident Cedric Anderson, who opened fire on his wife, 53-year-old Karen Elaine Smith at North Park Elementary School, media quoted San Bernardino Police Chief Jarrod Burguan as saying.

Anderson and Smith were found dead in a special needs classroom that serves the first through fourth grades, Burguan said.

Anderson entered the classroom "without saying anything" before he opened fire, Burguan added.

There were a total of 15 students and two aides in the classroom at the time, he added.

Two injured students were initially taken to hospital. One student -- eigh-year-old Jonathan Martinez -- succumbed to his injuries.

The other student was reportedly in a stable condition at the hospital. The students were not targeted but were standing behind Smith when Anderson opened fire, Burguan noted.