DENVER » Whatever the original impulse behind "Occupy Wall Street," or the speculation of what the movement might become, this much is true: The groups of protesters, now camping or hanging out in many U.S. cities, and the police agencies that have responsibility for public safety and order, are both shifting into new postures of action and response.

Whether that evolving chemistry will push things toward more confrontation remains unclear. But the combination — new participants, new police tactics — is clearly opening an uncertain chapter in a story that from its inception has embraced the notion of unplanned, unscripted civil action.

People like Darrel Egemo, 75, a former money manager, are part of this new ferment. Egemo came to the protests, now in their third week, on the grounds of the Colorado State Capitol here for the first time Tuesday.

"I decided they needed one person in a necktie and sport coat," Egemo said, looking dapper as he waved a sign to motorists, reading, "Integrity sold short by greed."

Larger numbers are pushing protesters into new areas as well, sparking tensions.

In Boston early Tuesday morning, about 100 protesters were arrested when the group expanded from its previous area in the center of Dewey Square in the financial district to a nearby part of the Rose Kennedy Greenway, part of the necklace of open park space through downtown.

By Tuesday morning, protesters were in sharp disagreement at their general assembly meeting whether the group should have expanded its turf and whether it had been a collective decision.

"More people are coming. We’re not shrinking," said Philip Anderson, an unemployed recent college graduate who has been acting as a spokesman. "If we grow into a place they don’t want us, it may come to another standoff like last night. We hope they don’t make the decision to use violence against us, but we’ll have to deal with whatever happens as it comes up."

In Los Angeles, where protesters as recently as last week were dominated by young people in what seemed a tie-dye and guitar-circle subculture, a second wave of older protesters and homeless people has gravitated toward the encampment at City Hall, demonstrators said.

Elise Whitaker, 21, a freelance script editor and assistant film director, said she thought it was about technology — older protesters took longer to tune in to the gatherings, she said, which had been organized largely through Internet social networks.

"It is the youth who spend the majority of our time on Facebook and Twitter," Whitaker said. "That’s why we knew about it first."

In Seattle, officials began on Monday pressuring protesters to relocate to City Hall from Westlake Park, in the busy downtown shopping district, after what had been a mostly peaceful, if statutorily illegal standoff.

The police showed up at 10 p.m. Monday and announced that the park was closed for the night, said Gabriel Bell, a volunteer legal adviser for Occupy Seattle. Anyone who stayed was at risk of being arrested, they were warned. After a fourth announcement at 11 p.m., Bell said, the protesters went across the street to avoid arrest. Many slept in doorways of nearby businesses, but the police kept their flashing lights going all night, making it difficult to sleep, protesters said.

Shifting coalitions and alliances are also complicating the internal politics of the movement.

In Chicago, for example, protesters from Occupy Chicago joined forces Tuesday with members of Action Now, a group concerned with vacant lots in Chicago’s South and West Side neighborhoods.

The combined groups piled at least a dozen garbage bags on the sidewalk in front of the Bank of America building in the Chicago Loop, along with couches and other trash that they said had been pulled from a foreclosed property. Five women, ranging in age from 56 to 80, were arrested after they went inside the bank lobby and scattered trash.

In Washington, where disparate groups of protesters with overlapping agendas from pacifism to poverty have been demonstrating in recent days, members of a group called Veterans for Peace joined in Tuesday, crowding the atrium of the Hart Senate Office Building, which they entered a few at a time before unfurling colorful banners and an upside-down U.S. flag.

"We want to stop the financial influence on our government and we want our people to be taken care of," said Leah Bolger, national vice president of Veterans for Peace.

In some places, the new alliances are making for some fine-point factional clarification. A spokesman for Occupy Chicago, Micah Philbrook, emphasized that his group had voted to join a week of protests organized by a coalition called Stand up Chicago, but had not become members of that coalition in participating in Tuesday’s activities, including the one at the Bank of America.

"We don’t want people to think that we are being co-opted by other movements," Philbrook said. "Occupy Chicago, like all the Occupy movements, stands apart from any political parties, stands apart from any existing movement."

A sometimes tentative police response is adding its own element to the mix.

In Atlanta, protesters were warned by the police Tuesday that if, at 11 p.m., they were still in Woodruff Park, a small oasis in the heart of downtown, they would be arrested. Anyone who did not want to be arrested could simply leave the park, the police said. But protesters said they were told the same thing Monday. Instead, dozens of police officers showed up but made no arrests.

The protesters seem to have significant numbers of uncounted allies, silent or on the sidelines, at least for now.

Daniel Eavenson, an engineer in Chicago, said he had only been "witnessing."

"There are millions of us watching online and sending out our hope," he said.

In New York, a "Millionaire’s March" of about 400 people affiliated with Occupy Wall Street wound its way throughB the Upper East Side Tuesday afternoon, with participants protestingB outside the homes of financial titans, including JPMorgan Chase’s Jamie Dimon, the media mogul Rupert Murdoch and the industrialist David H. Koch.

TheB march was peaceful, if noisy,B with protesters chanting, trumpetingB and drumming their wayB alongB FifthB Avenue and Park AvenueB under the watchful gaze of dozens of police officers and doormen like John Tima, working on Park Avenue.

"What are they going to accomplish out of this? What’s going to happen, higher taxes for rich people?B OK," he shrugged.

© 2011 The New York Times Company