"Give yourselves a hand," Executive Assistant Police Chief Terry Gainer told the crowd of protesters.
The demonstrators, their ranks thinned in a driving rain, disrupted the government's workday and private business in a big swath of the capital but failed to shut down the two days of meetings of the World Bank and International Monetary Fund.
A day that began with swinging clubs turned more amicable as police and the throngs they were watching orchestrated a good-natured arrest of several hundred who wanted to be taken into custody.
Police negotiated for an hour with protest organizer Mary Bull, who wore a plastic foam tree on her head, before proceeding with the arrests.
Gainer gave Bull some flowers and then placed her under arrest.
The protesters were charged with unlawful assembly and crossing police barricades. About 500 were arrested Monday, not all so peacefully, making a total of more than 1,000 for the three days of protests.
"We view this as a total success," said Robert Weissman, co-director of Essential Action, one of hundreds of groups in the protest coalition. "We have shined the light on these institutions as never before in this country."
Earlier, drum-beating marchers vented their fury about the treatment of the poor.
They accused the bank and the IMF of imposing crushing debts on poor nations, destroying the environment and perpetrating a host of other ills. "World Bank destroys tropical rain forest," said a two story-banner hung on a building under construction.
Unlike demonstrations Sunday when police let protesters take over empty streets, confrontations developed Monday over the din of traffic as Washingtonians went to work.
Traffic was disrupted and some government buildings and shops didn't open. When several hundred demonstrators came within a block of the IMF and menaced a police car, black-clad officers with helmets, billy clubs and visors responded with pepper spray and smoke canisters.
Tear gas wafted into the crowd as an officer tossed what he mistakenly thought was a smoke canister, police said.
Protesters, some donning gas masks and tying bandanas over their mouths, were chased down and clubbed. About 90 were arrested.
Even so, some protesters credited police with being more restrained than during the destructive demonstrations in Seattle against the World Trade Organization last fall.
"The police seem to be doing a much more stable job than the Darth Vader mode in Seattle," said actress-activist Susan Sarandon, who spoke to the demonstrators.
While many streets were normal, parts of the capital resembled a city facing a coup d'etat.
Riot police with their visors down marched along main streets in squads of one dozen, blocks were sealed with metal barriers and about 70 National Guard troops in camouflage guarded the World Bank and IMF.
Signs, banners, T-shirts and shouted slogans carried a long list of complaints against the two institutions, where finance ministers managed to get their business done.
World Bank spokeswoman Caroline Ansety said officials in the meetings felt "bewilderment and surprise at the degree of anger" outside. She said the officials were talking about ways to relieve poverty.
Some delegates were spirited to work before sunrise. "I certainly protested myself this morning at 4 a.m. when the alarm went off," said Canadian Finance Minister Paul Martin.
Police Chief Charles Ramsey showed off a collection of material he said had been seized from protesters--including rocks, nails, a slingshot and urine and bleach that he said were meant to be thrown in the faces of officers.
"They call it the Seattle facial," Ramsey said of the bleach.
It was clear from the outset that demonstrators knew they faced arrest. An organizer with a megaphone asked a gathering in back of the White House to separate into two groups--one willing to be arrested, one not. A determined group was willing and marched onto the streets.