Protesters march on the street over the Brooklyn Bridge during an Occupy Wall Street protest in New York Oct 1, 2011. [Photo / Agencies]

NEW YORK - About 500 anti-Wall Street protesters were arrested on Saturday afternoon after blocking traffic lanes on the Brooklyn Bridge and attempting an unauthorized march across the span, police and witnesses said.

On the second week of protests by the Occupy Wall Street movement, a large group of marchers broke off from others on the bridge's pedestrian walkway and headed across the Brooklyn-bound lanes.

"Some complied and took the walkway without being arrested. Others locked arms and proceeded on the Brooklyn-bound vehicular roadway. The latter were arrested," a police spokesman added.

Both the walkway and Brooklyn-bound car lanes were shut to traffic, snarling traffic. But police said it was expected to be opened soon.

Witnesses described a chaotic scene on the famous suspension bridge as a sea of police officers surrounded the protesters using orange mesh netting.

Some protesters tried to get away as officers started handcuffing members of the group. Dozens of protesters were seen handcuffed and sitting on the span as three buses were called in to take them away, witnesses and organizers said.

The march started about 3:30 pm (1930 GMT) from the protesters' camp in Zuccotti Park in downtown Manhattan near the former World Trade Center. Members of the group have vowed to stay at the park through the winter.

Celebrity support

In addition to what they view as excessive force and unfair treatment of minorities, including Muslims, the movement is also protesting against home foreclosures, high unemployment and the 2008 bailouts.

Filmmaker Michael Moore and actress Susan Sarandon have stopped by the protesters' camp, which is plastered with posters with anti-Wall Street slogans and has a kitchen and library, to offer their support.

On Friday evening, more than 1,000 demonstrators, including representatives of labor organizations, held a peaceful march to police headquarters a few blocks north of City Hall to protest what they said was a heavy-handed police response the previous week. No arrests were reported.

A week ago, police arrested about 80 members of Occupy Wall Street near the Union Square shopping district as the marchers swarmed onto oncoming traffic.

A police commander doused a handful of women with pepper spray in an incident captured on video and spread via the Internet, galvanizing the loosely organized protest movement.

The group has gained support among some union members. The United Federation of Teachers and the Transport Workers Union Local 100, which has 38,000 members, are among those pledging solidarity.

The unions could provide important organizational and financial support for the largely leaderless movement.

Similar protests are sprouting in other cities, including Boston, Chicago and San Francisco.