But the large number of arrests in Boston put a spotlight on the city yesterday.

Yesterday, protesters gathered in New York City, where protesters staged a “Millionaire’s March’’ past the homes of some of the nation’s wealthiest executives, jeering “tax the rich,’’ and in Washington, D.C., several demonstrators were arrested as they entered a Senate office building with banners. Demonstrations were also held in Seattle, Chicago, and on the steps of the state capitol in Oregon.

Among many grievances, protesters in Boston and across the country are decrying what they call vast disparities between rich and poor, lack of economic opportunities, and the influence of corporate money on politics. They describe themselves as representing the “99 percent’’ of ordinary people increasingly left behind by policies that benefit the wealthiest few.

But early in the morning, police carried out the arrests after protesters moved onto a large swath of the Rose Fitzgerald Kennedy Greenway and refused to leave.

The Boston demonstration, one of about 100 loosely affiliated similar gatherings in cities across the country, has been largely peaceful since hundreds rallied at Dewey Square and marched on the Boston Federal Reserve Building Sept. 30.

“I think it’s disgusting that Menino said civil disobedience won’t be tolerated,’’ said Andrew Farkas, 29, of Cambridge, who held up a sign that read “Civil disobedience made this country.’’ People here are just going to resort to more drastic actions. And it’s possible that things could turn violent.’’

The protesters’ next move remained unclear, but as news broadcasts and Internet traffic put Boston at the center of the scattered national movement, the crowd in Dewey Square yesterday appeared to have swelled and drawn energy from the arrests. Speakers stood on makeshift platforms and exhorted crowds, referring to the arrests as reasons to come together.

“For every one person arrested, there will be 10 more coming,’’ said Lisa Doherty, a 56-year-old Charlestown resident who lost a job as a mortgage processor three years ago. “We’re growing, even if they don’t want us to.’’

Protesters, including those who spent much of the day in court facing trespassing charges, said the arrests will only galvanize the movement and escalate its presence in Boston.

Mayor Thomas M. Menino, who has expressed sympathy for the movement’s goals of highlighting economic struggles of the middle-class, flatly stated yesterday that “civil disobedience will not be tolerated.’’

Police said the arrest of 141 in the early morning hours was the largest mass detention in recent memory, and it heightened tensions between protesters and city officials trying to walk a narrow line.

As Occupy Boston protesters denounced police yesterday for carrying out a swift overnight raid on their demonstration, city officials defended the crackdown as necessary to preserve public order against a restive grassroots movement.

“We did something we believe is the right thing to do, something that our brothers and sisters all over the country are doing in similar protests,’’ said Khury Petersen-Smith, 29, of Dorchester, who was among protesters arraigned in Boston Municipal Court.

Most accepted a recommendation by prosecutors to have their criminal charges converted to a lesser civil infraction with a $50 fine. At least 9 protesters declined that offer, saying they should never have been arrested at all.

Menino defended the police action, saying protesters crossed a line Monday afternoon when they sought to tie up traffic on the North Washington Street Bridge and then expanded their campground to a newly renovated section of the Greenway that authorities had specifically asked the activists to avoid.

“I understand they have freedom of speech and freedom of expression, but we have a city to manage,’’ he said.

Around 1:20 a.m., more than 200 officers, both in uniforms and riot gear, surrounded the section of the Greenway occupied by the protesters. Police Superintendent William Evans gave the crowd two minutes to disperse, warning that they would be locked up if they did not comply.

The crowd, energized by the sudden appearance of the Boston and Transit Police officers, chanted, “The people united will never be defeated,’’ “This is a peaceful protest,’’ and “The whole world is watching.’’

Ten minutes later, as many recorded them with video cameras, the first officers entered the park and surrounded the group. Evans, using a loudspeaker, gave one more warning and then police began putting protesters on their stomach, restraining their hands behind their backs and dragging them away as other officers tore down tents and arrested and detained people on the fringe of the park.

One police officer was hit in the face. According to police, no protesters or police were seriously injured.

Occupy Boston said in a statement that police had “brutally attacked’’ protesters.

“Today’s reprehensible attack by the Boston Police Department represents a sad and disturbing shift away from dialogue and towards violent repression,’’ the group said on its website.

Philip Anderson, a spokesman for the group, said police threw protesters to the ground and dragged them.

“It got kind of brutal,’’ he said.

Elaine Driscoll, a spokeswoman for the Boston police, said officers “have a right to protect themselves’’ and acted with restraint.

“We believe all our officers were respectful and proportional,’’ she said. The department had not received any complaints.

“We have been very accommodating to everyone’s right to demonstrate peaceably,’’ she said. “But when unpredictability starts to enter the scenario, we are obligated to maintain public order and protect public safety.’’

A city ordinance forbids sleeping in a local park between 11 p.m. and 7 a.m., giving police the authority to arrest protesters on charges of trespassing and unlawful assembly.

Driscoll said the protesters had maintained good communication with police until Monday, when hundreds of college students marched through Boston in a show of support.

The “breakdown in communication added to the level of unpredictability,’’ Driscoll said.

Driscoll said police will monitor the protests closely, but Menino made it clear the demonstrators will only be welcome for a certain amount of time.

Urszula Masny-Latos, a member of a group that provides legal advice to protesters, said she was arrested, even though she was wearing a green hat with the words, “legal observer.’’

“Four officers grabbed me and dragged me,’’ she said.

Andrew Ryan, Brian R. Ballou, John M. Guilfoil, and Martine Powers of the Globe staff contributed to this report. Peter Schworm can be reached at schworm@globe.com. Follow him on Twitter @globepete.

© Copyright 2011 Globe Newspaper Company.