[UPDATES BELOW] Today marks the two month anniversary of the Occupy Wall Street movement, and to mark the occasion demonstrators are planning a series of actions throughout the day, starting with a march on the New York Stock Exchange. Protesters say they intend to shut down the exchange before the opening bell, but that seems unlikely, as the NYPD has already declared the area around the exchange a "frozen zone."

Wall Street is heavily blockaded, and Justin Elliot reports that police are demanding to see work IDs from anyone trying to pass through. At 7:15 a.m., there were approximately 300 protesters amassing around Zuccotti Park. Updates to below; here's one LiveStream from the chaotic scene.

Update 7:28 a.m.: The crowd amassing across the street from Zuccotti Park has swelled to approximately 400-500.

Update 7:33 a.m.: A press area has been set up inside barricades out of sight of the Stock Exchange, and one protester is calling the NYC press "gutless cowards" if they "hide" in side the press section.

Update 7:40 a.m.: NYPD officers are forcing protesters to stay on the sidewalk because they don't have a parade permit.

Update 7: 44 a.m. The march is moving up Cedar Street, with the crowd chanting "All Day, All Week, Occupy Wall Street."

Update 7:55 a.m.: Christopher Robbins, who is on the scene for Gothamist, says some protesters are rebuffed at Nassau & Pine by NYPD mounted units and barricades. They're now headed to Water Street.

Update 8:00 a.m.: The heavy police presence has left the march with few options for actually marching anywhere near the Stock Exchange, but so far it's been nonviolent, with no attempts to jump the police barricades... yet.

Update 8:18 a.m.:
The march has split into different splinter marches. NYU Local's Zoe Schlanger is at William and Exchange, and "blocked on three sides" by police. She tweets, "Cops going to form a line and push the crowd down William. 'whenever you're ready, we'll squeeze em down that way' "

Update 8:35 a.m.: Two splinter marches have merged by the intersection of Beaver and Broad Street, where the unofficial crowd estimate is 700-1,000. Using the "people's mic," a protester announced that four intersections have been blocked by protesters. The march is continuing, with one group headed to Wall Street and Broadway.

Update 8:38 a.m.:On Twitter, Nick Pinto says, "One of the direct action organizers confirms the obvious: plan is to leave crowds at every intersection, blocking access to NYSE."

Update 8:45 a.m.: Cops have clashed with protesters at Broad Street, shoving them back from the barricades. Robbins says some protesters have flooded the street near the Bull statue and are blocking traffic on Broadway by Exchange.

Update 8:57 a.m. There are reports of several arrests at various intersections near the Stock Exchange. Here's video of police pushing the crowd back at Broad Street, by Justin Elliot:

Update 9:14 a.m.:At Broadway and Wall Street, approximately 150 protesters are blocking access to the NYPD barricades. Rumor has it protesters are going to stand on line at checkpoints to get their IDs checked by the NYPD, in order to slow down process.

Update 9:25 a.m.: John and Eric Tabacco, two brothers who own the website Locatestock.com, have showed up at the protest holding signs urging protesters to get a job and "occupy a desk." Eric tells us, I''m sick of these people with no teeth and no job, these vagrants coming into my city, urinating on our streets. I was born and raised on the Lower East Side, and this is my city. Every protest has a pushback, and we're the pushback."

Update 9:38 a.m.: Shortly after 9 a.m., there was jubilant cheering from protesters under the impression that the NYSE opening bell had been delayed. But the bell is rung daily at 9:30 a.m., and that just happened, as usual.

The largest accumulation of protesters is now at Beaver and Broad, and it's unclear what their next move is. But here's video of Russell Simmons, who also Tweeted, "my political director @MichaelSkolnik said I can't get arrested cause I gotta go to heavy's funeral...":

Update 9:45 a.m.: NYPD is violently clearing the street at Beaver and Broad, shoving protesters onto the sidewalk, making multiple arrests as crowd chants, "SHAME!"

Update 10:00 a.m.: On Beaver Street between Williams and Broad, police are arresting a bunch of people. Robbins says, "One young man was hit with a baton repeatedly and [cops] stomped on his back." It looks like they are blocking off Wiltiam Street and arresting people in the street.

Update 10:15 a.m.: At Beaver and William Street, cops have just warned protesters via bullhorn that they will arrest anyone remaining in the street. Protesters have locked arms and the cops are now making arrests.

While there have been some violent incidents, Robbins says that it appears cops are trying to be as restrained as humanly possible, even stopping more aggressive colleagues (apparently a cop lunged at protesters, but another cop yanked him back by the collar). Robbins adds that before the police warning about arrests, a police officer in a suit asked protesters if they were staying—when protesters said yes, he made a call on his cell and said, "They're not going to move back," seemingly getting feedback from even higher-ups about next steps.

Update 11: 15 a.m.: A NYSE trader tells Daily News reporter Christina Boyle the "trading floor was 'a little more animated' this morning because of the march."

Meanwhile, 700-800 protesters have amassed in Zuccotti Park, where a confrontation with police is erupting on the south side of the park. Robbins reports "wild cheering as barricades taken down." Now the NYPD is violently pushing protesters back into the park and off the sidewalk. (Here's photos of the NYPD trying to figure out how to arrest a woman in a wheelchair earlier.)

Update 11: 45 a.m.: The situation at Zuccotti Park has turned into a celebratory dance party, with some protesters exuberantly dancing on the barricades they seized. Earlier, N+1 co-founder Keith Gessen was arrested.

Update 11:50 a.m.: Okay, enough dancing. We're told many of the protesters are marching out of the park to Wall Street. Yes, again.

Update 12 p.m.: A rough estimate of the march to Wall Street puts the crowd at 1,000. Bethany O'Grady tells us they were turned back by barricades and "no one knows where they're going they're just being herded like sheep. I've asked at least 20 protesters if they know where they're marching and they don't know. Mic check is saying if you have an unlimited Metrocard to use it and enter the subway at Wall Street."

We just got off the phone with the NYPD press office; they told us they have no official count of arrests so far. But police sources tell City Room at least 75 were arrested.

Update 12:15 p.m.: Here's video of retired Philadelphia police captain Ray Lewis getting arrested, courtesy John Knefel:

Update 1:30 p.m.: The NYPD has confiscated a truck that protesters were allegedly using to transport tents and chains, according to O'Grady, who sent us this photo of the Budget rental truck in question. The Daily News reports that "a cop jumped on the driver's side step of a Budget Truck on Broadway off Pine. As other cops ran behind the truck, the driver was forced to pull over. The driver said he was Joshua Fellows of Youngstown, Ohio." When asked if he was a protester, Fellows replied, "I plead the Fifth."

Update 1:52 p.m.: We're seeing reports that the NYPD has moved in on the protesters in Zuccotti Park and is making arrests. "Cops are trying to clear Zuccotti Park," tweets Daily News reporter Christina Boyle. "Very tense. Saw one man in the middle badly bleeding from the head." It's unclear why police are clearing the park now. Another witness tweets: "RIOT COPS STORM THE PARK. No idea WTF just happened."

And Reuters' Anthony DeRosa tweets, "Police are entering Zuccotti Park, they have closed the entrances and exits. Protesters saying "This is illegal, this is a fire hazard."

Update 2:04 p.m.: We're seeing multiple reports that an NYPD officer was stabbed in the head or hand. An FDNY spokesman confirms they're responding to a call about a person with a "laceration on a finger" but he could not verify that the victim was NYPD. There are about 100 cops with riot gear in the park now, and we're told they're not letting anyone in or out.

Update 2:15 p.m.: There is still a very heavy police presence inside the park. According to this UStream on Reuters, the man who was taken out of the park under arrest and bleeding from the head had been kicking the barricades. Police tackled him, and he hit his head during the arrest. (Another witness says cops "beat the shit out of him.")

The entry points to the park have now been reopened, and speculation that riot police were about to make mass arrests seem to be unfounded.

Update 2:27 p.m.: Police sources confirm to the Times that a police officer was cut in the hand by a protester wielding a piece of glass, "possibly a broken bottle." The assailant is in custody, and the officer is in stable condition, though he'll reportedly require about 20 stitches.

Update 3 p.m.: Witnesses say the protester who was arrested bleeding from the head had knocked a police officer's hat off and then ran into the crowd. Police chased him down and allegedly beat him. Here's a photo of the unidentified man as he was being escorted out.

In other news, a female Occupy Wall Street protester "was chased, tackled and arrested after she doused four cops with a possible 'vinegar-based' liquid," police sources tell the Daily News.

Update 3:36 p.m.: And here's video of the young man being escorted out of the park in handcuffs, blood streaming from his head. This website—which claims his head was "split down to the white meat"—has another video of the chaotic arrest.

(On-the-scene reporting by Christopher Robbins and Bethany O'Grady)