SAN FRANCISCO -- Security officers seeking increased wages and better training walked off the job Monday, staging picket lines in front of 14 buildings in San Francisco's Financial District.

Picket lines were located in front of 1 Front St., 333 Market St., 50 Fremont St. and 11 other buildings, Service Employees International Union Local 24/7 spokeswoman Gina Bowers said.

The number of picket lines was expected to grow throughout the day, she added.

Security officers voted Sept. 15 to authorize union leaders to call an unfair labor practice strike at anytime.

"The real issue is that large corporations that own buildings need to take responsibility for security in their buildings, and make sure that security jobs are good jobs for the safety of the Bay Area," Bowers said.

In addition to better training and increased wages, SEIU Labor 24/7 is asking for adequate health benefits for the 4,000 Bay Area security officers it represents, Bowers said.