More than 2,400 Kaiser Permanente psychologists, therapists, social workers and other mental health workers in Southern California have begun an open-ended strike over increased workloads and staffing shortages.

The National Union of Healthcare Workers said nearly 2,400 mental health workers launched the job action after Kaiser Permanente management turned down their proposals.

Workers gathered outside Kaiser hospitals in San Diego and Los Angeles counties Monday morning, launching what is to be an “open-ended” strike of Kaiser mental health care workers throughout Southern California.