A search is underway for a shooter after one person was killed and three others were injured following a graduation ceremony at a high school in California.

A teenager was killed and three people were wounded, including an 11-year-old, when gunfire erupted outside a high school graduation ceremony in Northern California, according to police.

The incident occurred around 7:15 p.m. at Fairfield High School, where the Fairfield-Suisun Unified School District was hosting a graduation ceremony for Sem Yeto High School.