Hundreds of Occupy Wall Street protesters marched through Lower Manhattan towards the stock exchange Thursday morning as they marked the movement's two month anniversary on what is being called a "National Day of Action." The scene at one point got tense, as protesters clashed with the police at Zuccotti Park--the same park where the protesters were evicted from earlier this week.

From Reuters: "Scores of police barricaded the narrow streets around the stock exchange and used batons to push the protesters onto the sidewalk as they marched from a nearby park in a bid to prevent financial workers from getting to their desks."

The New York Times reported: "The marchers then returned to the park, where they yanked out barricades that had been placed there on Tuesday in order to create single-file entrances. Perhaps a thousand protesters streamed into the park, followed by officers who began making more arrests. Officers could be seen shoving and hitting protesters and journalists."

And more from CNN: "By late Thursday morning, the Zuccotti Park crowd could be seen surging forward against a large police presence, as authorities struggled to contain the group. By noon, however, police had regained control of much of the area."

At least 75 people were arrested, including a woman in a wheelchair, USA Today reported. (Note: other reports have put the figure of arrests between 175 and 200.) One video showed police dragging a woman away by what appeared to be her jacket or backpack. The video was shot by CNN iReporter Alvaro Perez.

Demonstrators in New York have other events planned throughout the day. At 3 p.m., the group plans to Occupy the Subway, before heading over to Foley Square around 5 p.m. Protesters will then march over to the Brooklyn Bridge. According to CNN, more than 700 arrests were made last month when demonstrators attempted to cross the bridge.

Other Occupy demonstrations are taking place around the country Thursday.

Here's video from Thursday's morning event from CBS News:

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