The collision involving at least two vehicles was reported at about 1:35 p.m. on the northbound 405 Freeway near Mulholland Drive, said Nicholas Prange of the Los Angeles Fire Department.
One person suffered serious injuries in the collision and another suffered moderate injuries, while the remaining patients had only minor injuries. The LAFD reported some of the patients were taken to a hospital, but could not confirm the exact number or their conditions.
The carpool lane of the northbound freeway was temporarily closed following the crash, according to the California Highway Patrol, and the LAFD reported traffic in both directions would be impacted for an unknown duration.
The cause of the collision was under investigation.