NEW YORK — More than 700 protesters demonstrating against corporate greed, global warming and social inequality, among other grievances, were arrested Saturday after they swarmed the Brooklyn Bridge and shut down a lane of traffic for several hours in a tense confrontation with police.

The group Occupy Wall Street has been camped out in a plaza in Manhattan’s Financial District for nearly two weeks staging various marches and had orchestrated an impromptu trek to Brooklyn on Saturday afternoon. They walked in thick rows on the sidewalk up to the bridge, where some demonstrators spilled onto the road after being told to stay on the pedestrian path, police said.

The majority of those arrested were given citations for disorderly conduct and were released, police said.

Some protesters sat on the road, chanting “Let us go,” while others chanted and yelled at police from the pedestrian walkway above. Police used orange netting to stop the group from going farther down the bridge, which is under construction.

Some of the protesters said they were lured onto the roadway by police, or they didn’t hear the calls from authorities to head to the pedestrian walkway. Police said no one was tricked into being arrested, and those in the back of the group who couldn’t hear were allowed to leave.

“Multiple warnings by police were given to protesters to stay on the pedestrian walkway and that if they took roadway they would be arrested,” said Paul Browne, the chief spokesman of the New York Police Department.

Erin Larkins, a Columbia University graduate student who says she and her boyfriend have significant student loan debt, was among the thousands of protesters on the bridge. She said a friend persuaded her to join the march and she’s glad she did.

“I don’t think we’re asking for much, just to wake up every morning not worrying whether we can pay the rent, or whether our next meal will be rice and beans again,” Larkins wrote in an email to The Associated Press. “No one is expecting immediate change. I think everyone is just hopeful that people will wake up a bit and realize that the more we speak up, the more the people that do have the authority to make changes in this world listen.”

Several videos taken of the event show a confusing, chaotic scene. Some show protesters screaming obscenities at police and taking a hat from one of the officers. Others show police struggling with people who refuse to get up. Nearby, a couple posed for wedding pictures on the bridge.

“We were supposed to go up the pedestrian roadway,” said Robert Cammiso, a 48-year-old student from Brooklyn told the Daily News. “There was a huge funnel, a bottleneck, and we couldn’t fit. People jumped from the walkway onto the roadway. We thought the roadway was open to us.”

Earlier Saturday, thousands who joined two other marches crossed the Brooklyn 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 organized by United Way.