Thousands of demonstrators have marched on New York's Brooklyn Bridge after a day of protests to mark two months since the beginning of the Occupy Wall street movement against economic inequality.

At least 200 protesters were arrested, many of them as they tried to block traders from reaching the city's stock exchange.

Lines of police and barricades were ranged against the demonstrators, who were evicted from their encampment at Zuccotti Park on Tuesday.

Deputy Commissioner of Public Information for the New York Police Department, Paul Browne, said the officers were instructed to allow lawful protest, but arrest people who broke the law.