Police have arrested about 700 protesters who swarmed New York's Brooklyn Bridge and shut down a lane of traffic for several hours.
Some demonstrators spilled on to the roadway after being told to stay on the pedestrian pathway, police said. They face charges of disorderly conduct and resisting arrest. The lane has since reopened.
Occupy Wall Street demonstrators are protesting against corporate greed, global warming and social inequality, among other grievances.
The group has been camped near the city's Financial District for two weeks and clashed with police on earlier occasions.
Yesterday, two other marches went over the bridge without problems. One was from Brooklyn to Manhattan by a group opposed to genetically-modified food. Another in the opposite direction marched against poverty.