[Updated at 8:53 p.m. ET] A total of 245 Occupy Wall Street demonstrators were arrested Thursday in New York, including 64 arrested during an early evening sit-in on Centre Street near Foley Square in lower Manhattan, a police spokesman said.

Earlier Thursday, New York police spokesman and protest organizers said that 99 people were arrested during the same sit-in. In fact, 64 were arrested - all of them wearing 99% t-shirts - in that incident.

[Updated at 6:54 p.m. ET] New York police arrested 99 more Occupy Wall Street protesters early Thursday evening, a high-ranking member of the city police department said. Earlier Thursday, police said 177 people had been arrested.

Occupy Wall Street organizers had said that 99 people were prepared to be sit down in a street and be arrested - a symbolic number, as the activists purport to represent the interests of 99% of the nation's population, as opposed to the wealthiest 1%.

[Updated at 5:35 p.m. ET] Several people have been charged with felonies in connection to incidents that have occurred at recent Occupy Denver protests, Denver District Attorney Mitch Morrissey told CNN.

Two people were charged in connection to incidents that took place on November 13, and one was charged in connection to an incident on October 29. The felony charges include inciting a riot and second-degree assault on a peace officer.

News of the Denver charges came on a day that the Occupy movement has called its national "mass day of action", which has involved protests in several large U.S. cities, marking two months since the Occupy movement began in New York.

In New York on Thursday, 177 people were arrested during Occupy protests, and five police officers were injured when a liquid was thrown on their faces during confrontations with protesters, police Commissioner Ray Kelly said.

In Portland, Oregon, 25 people were arrested Thursday morning at the east end of the Steel Bridge, where Occupy Portland protesters were gathered, police Lt. Robert King said. All 25 were cited with disorderly conduct.

[Updated at 4:32 p.m. ET] The number of protesters arrested during "Occupy Wall Street" demonstrations in New York on Thursday has reached 177, Police Commissioner Ray Kelly said.

Five police officers were injured when a liquid was thrown on their faces during confrontations with protesters, Kelly said. The officers experienced a burning on their faces, but were able to wash off the unknown substance at a nearby hospital.

Thursday was the occupy movement's national "mass day of action", marking two months since the movement began in New York. Hundreds of protesters participated in New York on Thursday - their first major show of strength since police evicted demonstrators from Zuccotti Park, where a court has said they may demonstrate but no longer camp out.

New York Mayor Michael Bloomberg said "some protesters today deliberately pursued violence," but added that most were peaceful and have "caused minimal disruptions to our city."

Protesters in New York demonstrated Thursday morning at their former home base, while others marched toward the New York Stock Exchange. Other planned events in New York included "occupy the subways," a plan to gather at 16 hubs at 3 p.m.; and "take the square" at 5 p.m., a reference to Foley Square, across from City Hall. Organizers also plan a march across the Brooklyn Bridge after the gathering at Foley Square.

Clashes between protesters and police happened Thursday at Zuccotti Park - where demonstrators were trying to lift barricades - and on a street in Lower Manhattan.

Explain it to me: Occupy movement

Roundup of Thursday's Occupy protests

[Updated at 3 p.m. ET] About 175 Occupy Wall Street protesters have been arrested in New York on Thursday, a day that demonstrators have called a national "mass day of action", New York police said.

Seven New York police officers have been injured during clashes with protesters, police spokesman Paul Browne said.

Demonstrations in New York and other U.S. cities, such as Los Angeles, Dallas and Portland, Oregon, were marking two months since the movement began in New York.

[Updated at 2:40 p.m. ET] Demonstrators and police clashed on a street in Lower Manhattan on Thursday afternoon, according to CNN producer Brian Vitagliano, who was at the scene. Four ambulances and a separate emergency response vehicle responded to the incident.

[Updated at 1:54 p.m. ET] Occupy Wall Street demonstrators and police have scuffled again Thursday in New York's Zuccotti Park, where waves of protesters faced off against columns of police in and around the Lower Manhattan park.

Thursday afternoon's scuffling - following a morning confrontation at the park - came as police attempted to put up metal barricades.

Protesters had lifted metal barricades in the morning, defying authorities and blocking traffic

[Updated at 1:34 p.m. ET] Twenty-five people have been arrested at an Occupy protest in Los Angeles on Thursday morning, police Officer Rosario Herrera tells CNN.

The arrests came on what Occupy Wall Street protesters are calling a national "mass day of action" meant to mark two months since the movement began.

In Los Angeles, two people were arrested on suspicion of interfering with police officers, and 23 people were arrested on suspicion of unlawful assembly.

A heavy police presence also he been put in place in New York, where about 75 protester arrests were reported Thursday morning; Dallas; and Portland, Oregon.

In Dallas, CNN affiliate WFAA broadcast images of police sweeping through city squares where protesters had been gathering and camping. In Portland, protesters' plans for Thursday include "occupy banks." "Let's shut them down!" the organizing website n17pdx.org says.

Large groups of demonstrators gathered in front of Portalnd's downtown hotels, carrying placards and chanting, "We are the 99%."

[Updated at 11:52 a.m. ET] New York police have arrested about 75 demonstrators Thursday, many of whom were detained on streets near the New York Stock Exchange, authorities say.

The arrests came on what Occupy Wall Street protesters are calling a national "mass day of action" meant to mark two months since the movement began. The "mass day of action" also comes two days after police temporarily evicted protesters from New York's Zuccotti Park and a court order prohibited demonstrators from camping there.

On Thursday morning, protesters had gathered outside the New York Stock Exchange, where some had said they hoped to disrupt the opening bell. But security was tight, and the stock exchange opened as scheduled.

Residents and employees are using identification cards and badges to access Wall Street areas near the Exchange, as police have erected barricades around the area, said police spokesman Paul Browne.

[Initial post, 11:26 a.m. ET] Occupy Wall Street demonstrators lifted metal barricades at Zuccotti Park in New York Thursday, as police scuffled with hundreds of protesters swarming the Lower Manhattan park.

The crowd, having tried to remove the barricades from some places at the park, could be seen surging forward against and standing face-to-face with a large police presence.

By late Thursday morning, authorities had arrested up to 60 demonstrators in New York, police spokesperson Paul Browne said.

Police say at least four police officers were rushed by ambulance to a nearby hospital after an unidentified liquid was thrown at them