Thousands of Occupy Wall Street protesters are holding demonstrations in the United States and around the world as part of a global day of action marking the two-month anniversary of the start of the movement in a Manhattan park.

In New York's financial district Thursday, hundreds of anti-capitalist demonstrators pushed back against police and dismantled barriers that officers had erected around Wall Street. New York police say at least 175 protesters were arrested during the confrontations.

The development comes two days after the city evicted protesters from lower Manhattan's Zuccotti Park, which has been the epicenter of the movement. They were allowed to return to the public space, but prohibited from camping there. The protesters said they planned to take Thursday's demonstrations to New York's subways and major bridges.

Elsewhere, police in Los Angeles, California arrested at least 20 anti-Wall Street protesters while clearing a mini-camp in the downtown area. Similar demonstrations were taking place in Portland, Oregon and other U.S. cities. Demonstrators in Washington, DC were marching on the Key Bridge connecting Washington and Virginia as part of a nationwide “Get on the Bridge” call to action.

Overseas, anti-capitalists demonstrators camped outside St. Paul's Cathedral in London refused to leave despite the expiration of a Thursday deadline for them to take down their tents or face legal action. Rallies also were planned in Belgium, Germany and Spain.

In the U.S., tension between demonstrators and local authorities has escalated as police clear protester encampments. The clearing of the Occupy camp in New York follows similar evictions in Portland, Atlanta as well as Oakland .