LOS ANGELES, United States, June 4, 2026 (BSS/AFP) - Gunfire after a graduation ceremony at a northern California high school killed a teenager and wounded three other people on Wednesday in a parking lot at the campus, police said.

In addition to the 18-year-old slain at Fairfield High School -- which is around 50 miles (80 kilometers) northwest of San Francisco -- the shooting wounded people aged 11, 20 and 25, said police.

Gun violence kills thousands of people every year in the United States, where a constitutional right to bear arms trumps demands for stricter rules.

Police were alerted to the shooting at Fairfield High School around 7:15 pm (0215 GMT), Michelle Belyea, a police officer with Fairfield Police, told a news conference.

"There are four victims of gunshot wounds," Belyea said.

A man who attended the ceremony told local TV station KCRA he heard shots fired as photographs were being taken in the school parking lot.

Amanda Prieto, who lives near the school, told the outlet she saw people "screaming and running through the parking lot" as shots rang out.

Belyea said there was an "active investigation" into the shooting and no ongoing threat to the community, without providing information on the suspect or victims' injuries.