Gunshots were fired at Santa Monica College west of Los Angeles on Friday, leaving an unspecified number of people injured, and a suspect was taken into custody, police said.
Santa Monica police spokesman Richard Lewis said no further information was immediately available on the shooting, which took place as President Barack Obama was attending a fundraiser across town.
A spokeswoman for the California Highway Patrol, Sergeant Denise Joslin, told Los Angeles television station KCBS that the CHP had received a report of a man armed with several guns shooting into traffic and at a bus.
She said there were no reports of fatalities, "but that is not something that I would rule out."
"We are not sure that it was a single shooter yet," Joslin added.
Obama was attending a fundraising event at the Santa Monica home of former News Corp President Peter Chernin at about the time of the shooting and had just finished his remarks, but he made no mention of the incident.
A Secret Service spokesman in Washington said: "We are aware of the incident and it is not impacting the visit. It's a local police matter at this point."