A spokeswoman for the Service Employees International Union Local 1021 in San Francisco said the transport workers would remain on strike until further notice.
"I wish I had news for you, but BART [Bay Area Rapid Transit] hasn't offered any new proposals to bring about a resolution and we're on the second day of our strike," said spokeswoman Cecille Isidro.
"They have not come back with any proposals that address critical safety issues and fair pay," she said.
In contrast, BART officials in a statement said the transit company was "working hard to bring a fair and responsible resolution to labor talks."
The statement also blamed the union for the predicament, the Los Angeles Times reported Tuesday.
"We're sorry that the actions of ATU [Amalgamated Transit Union Local 1555] and SEIU [Service Employees International Union Local 1021] have caused such a tremendous disruption to the people of the Bay Area," the statement from BART said.
"This strike is not necessary, and we call on union leaders to end it and join us at the table so the Bay Area can get moving again," said BART spokesman Rick Rice.
"Our members aren't interested in disrupting the Bay Area, but management has put us in a position where we have no choice," countered President of ATU 1555 Antonette Bryant.