Traffic on both lanes of California's Golden Gate Bridge has been shut down Monday, the California Highway Patrol tells Fox News Digital, as images emerging from the scene show anti-Israel protesters holding banners with the messages "Stop the world for Gaza" and "End the siege on Gaza now!"

A similar demonstration has also blocked traffic on Interstate-880 in Oakland. 

"Golden Gate Bridge is closed in both directions for an undetermined amount of time," the San Francisco Department of Emergency Management said in a statement, adding that a "civic demonstration" is ongoing.

In the Oakland protest, seven demonstrators are attached to concrete barrels that have been placed in the middle of the roadway, according to KRON. 

A flag attached to a fence there says "A-15 economic blockade for a Free Palestine."

The A15 Action group says on its website that "There is a sense in the streets in this recent and unprecedented movement for Palestine that escalation has become necessary: there is a need to shift from symbolic actions to those that cause pain to the economy.

"The global economy is complicit in genocide," it adds. "Join participating cities in blocking the arteries of capitalism and jamming the wheels of production.

Real-time traffic data from Google Maps shows extensive delays building up in the Bay Area as a result of the protests.

Another protest reportedly linked to the group unfolded in Philadelphia on Monday, according to the Philadelphia Inquirer.

This is a developing story. Please check back for updates.