LOS ANGELES -

University of California medical center workers have begun a two-day strike that could involve thousands of employees and prompted postponement of some surgeries.
    
A union representing some 13,000 pharmacists, nursing assistants and other workers struck at 4 a.m. Tuesday in San Diego, Irvine, Los Angeles, San Francisco and Sacramento.
    
Ruben Gomez, a radiation therapist in Los Angeles, tells KCBS-TV that strikers are fighting for more staff and believe levels are chronically low. UC officials say the issue is the union's refusal to accept a less-lucrative pension plan.
    
Officials prepared for the strike by postponing nonessential surgeries. Gomez says the strikers also have a task force set up to ensure care for critically ill patients.