As the Occupy Wall Street protest in New York entered its third week Saturday, police arrested more than 700 protesters for closing down the Brooklyn Bridge and a lane of traffic for several hours.

Standing in the middle of the road, protesters blocked traffic heading to Brooklyn from Manhattan. The bridge over which more than 130,000 vehicles cross every day was finally reopened at 8:05 p.m., police said.

About 1,500 demonstrators reached the bridge at around 4 p.m., banging drums and chanting, The whole world is watching.

Despite being told to stay on the pedestrian walkway, demonstrators spilled onto the roadway, creating a block on the bridge, which forced people to walk into the vehicle lanes.

Police then moved in to arrest protesters for disorderly conduct and blocking traffic.

Protesters who took the walkway were not arrested. Others who used [the] Brooklyn-bound vehicular roadway were arrested, said Paul Browne, deputy commissioner for public information at the New York Police Department.

It was possible that protesters in the back of the column might not have heard the warnings, said Christopher Dunn, associate legal director of the New York Civil Liberties Union. But Browne contended that those protesters were not arrested.

Witnesses earlier thought that police officials who were walking ahead of the protesters were actually leading them, but about one-third of the way across the bridge, the police took out orange nets and trap the protesters, who were then arrested.

It seemed as if they deliberately moved back to allow people onto the roadway, Etan Ben-Ami, a psychotherapist from Brooklyn, told the Daily News.

Saturday's incident occurred during a campaign against what protesters call social inequities resulting from the financial system, CNN reported.

Protesters who had planned to cross the bridge first held a rally at Zuccotti Park and then marched toward the bridge.

The protesters have been camping out in Lower Manhattan since Sep. 17. Initially, they thought they would camp outside Wall Street itself, but police blocked their way. They later moved to Zuccotti Park between Trinity Place and Broadway, a few blocks south of the World Trade Center site.

U.S. Rep. Charles Rangel, D-New York, told protesters, This is a peaceful march, CNN reported.

During the two weeks of their encampment, the protesters had addressed various issues, including police brutality, union busting, and the economy, participants said.

The NYPD did not plan to forcibly remove the protesters from the park, Police Commissioner Raymond Kelly told Forbes, but it's our job to make sure that people demonstrate peacefully.