Hundreds of Occupy movement protesters are rallying in New York Thursday, as part of a national day of action supported by other demonstrations across the country.

In New York's financial district, the situation intensified as hundreds of anti-capitalist demonstrators pushed back against police and dismantled barriers that officers had erected around Wall Street.

Thursday is the two-month anniversary of the Occupy Wall Street movement, and protesters have promised a major show of strength.

New York police say at least 50 protesters were arrested as the group attempted to disrupt the New York Stock Exchange.

The latest development comes two days after the city evicted protesters from Zuccotti Park in Lower Manhattan, where they had been living in tents since September. They were allowed to return to the public space, but were prohibited from camping there.

The protesters say they plan to take Thursday's demonstration to New York's subways and major bridges.

Other demonstrations were taking place Thursday in Los Angeles, Portland and other U.S. cities. Demonstrators in Washington D.C. plan to march on the Key Bridge connecting Washington to Virginia as part of a nationwide “Get on the Bridge” call to action.

Rallies also were planned overseas in Belgium, Germany and Spain.

In the U.S., tensions between protesters and local authorities have escalated as police move to clear protester encampments. The clearing of the Occupy camp in New York follows recent evictions in cities such as Portland, Atlanta and Oakland .

After police dismantled the Zuccotti Park camp Tuesday, demonstrators filed a motion seeking to be allowed back in with their tents and sleeping bags. But a judge ruled that the New York park's ban on sleeping did not violate the protesters' constitutional right to free speech.

New York Mayor Michael Bloomberg said he agrees with the judge's decision that free speech does not include the right to “endanger the public or infringe on the rights of others by taking over a public space.”

Zuccotti Park has been the epicenter of the Occupy protest movement, sparking similar occupations of other public spaces throughout the United States and in other countries.