Occupy Wall Street protesters outside the Port of Oakland are pledging to stay until at least 10 p.m. PDT Wednesday.
Demonstrators had marched to the port earlier with the intention of closing the facility down during an evening shift change.
Port spokesman Isaac Kos-Read acknowledged Wednesday evening that "maritime operations at the port are effectively shut down."
Oakland police had estimated that the number of demonstrators gathered at the port was around 3,000 people, though some in the crowd began leaving as the night progressed.
Police estimated that about 4,500 people had protested across the city Wednesday.
Police have been describing the protests as peaceful. No arrests have been reported.