Updated 5:30 PM ET
(CBS/AP) MADRID - On the front lines of the world's May Day protests this year, along with the traditional chants, banners and marches, a gamut of emotions flowed through the crowds: Anger. Fear. Elation. Despair.
With Europe's unemployed denouncing austerity measures, Asia's laborers demanding higher salaries and U.S. protesters condemning Wall Street, Tuesday's demonstrations by hundreds of thousands were less a celebration of workers' rights than a furious venting over spending cuts, tax hikes and soaring unemployment.
The protests came just days ahead of key elections in Greece and France, whose leaders have acutely felt popular anger over policies many feel are strangling any hopes of economic recovery. The rallies reflected deep pessimism in Spain, dealing with a fragile economy is in the cross-hairs of the European debt crisis.
Yet optimism and national pride emerged too. Over 100,000 turned out in Russia for May Day rallies that celebrated Vladimir Putin's government. And tens of thousands of workers rallied with joy in France, hoping this would be the last week of President Nicolas Sarkozy's conservative leadership.
In the United States, demonstrations, strikes and acts of civil disobedience were planned, including what could be the country's most high-profile Occupy rallies since the anti-Wall Street encampments came down in the fall.
In New York, hundreds of Occupy Wall Street protesters and their supporters spilled out onto Fifth Avenue in a confrontation with police before being forced back onto the sidewalk.
Marchers blocked traffic before police in riot gear pushed the crowd back onto the sidewalks. The group chanted: "We are the people. We are united!"
Around 100 protesters gathered in Bryant Park before heading off to picket at banks and other businesses in Manhattan, CBS Station WCBS New York reported. There were calls from organizers to protesters to disrupt traffic, but no incidents have been reported.
"A lot of what we see is wrong with the system is because corporations have so much influence over Congress," OWS organizer Alexis Goldstein told WCBS.
Threatening letters containing a white powder that appeared to be corn starch were sent to some institutions.
Three letters were received Tuesday, two at News Corp. headquarters and addressed to the Wall Street Journal and Fox News, and one to Citigroup. The message in the letters said: "Happy May Day."
Seven letters were received Monday at various banks. One was sent to Mayor Michael Bloomberg.
In Philadelphia, police say two demonstrators have been arrested during Occupy Philadelphia protests. More than 100 protesters marched and rallied outside a downtown bank Tuesday and then marched through the center of the city. Traffic was gridlocked as protesters gathered at a Wells Fargo bank branch, then marched several blocks away and sat in the middle of a busy street.
In Atlanta, about 100 people rallied outside the Georgia Capitol, where a law targeting illegal immigration was passed last year. They called for an end to local-federal partnerships to enforce immigration law.
Meanwhile, five men, at least three of them anarchists, plotted to blow up a bridge near Cleveland, but there was no danger to the public because the explosives were inoperable and were controlled by an undercover FBI employee, the agency said Tuesday in announcing the men's arrests.
Occupy Cleveland media coordinator Jacob Wagner said at least some of the suspects had attended the group's events but that they weren't affiliated with or representing the group.
In Boston, activities are being planned that will include a noon rally at City Hall, and a "Death of Capitalism Street Theater Funeral Procession" later in the evening, according to CBS Station WBZ Boston. Occupy Boston called for people to skip work and school, strike and not shop
In San Francisco, the Golden Gate Ferry service was shut down Tuesday morning with protesters joining striking ferry workers, CBS affiliate KCBS San Francisco reported. Service would remain shut down until 2 p.m and could affect 6,000 riders. Also, 50 transit workers picketed outside of the San Francisco Ferry Building.
Organizers backed away from earlier calls to block the Golden Gate Bridge, but scores of police -- some carrying helmets and batons -- lined the span during the morning rush hour. Some protesters with signs stood nearby, but did not disrupt traffic.
In Oakland, stinging gas has sent May Day protesters fleeing a downtown intersection as police took at least four people into custody.It was unclear whether police fired the gas Tuesday as several hundred protesters blocked traffic near Oakland City Hall.
Also in the city, workers, patrons and property owners clashed with a few dozen May Day protesters who stormed a downtown Oakland diner in an attempt to shut down the restaurant. The two sides scuffled briefly Tuesday morning before police moved in, and the restaurant, Rudy's Can't Fail Cafe, stayed open. Demonstrators were upset that the diner had not closed its doors despite calls for a May Day "general strike."
In Los Angeles, a boulevard near Los Angeles International Airport has been shut down as union workers stage a May Day strike and protest. Several hundred airport employees are marching on Century Boulevard and police have shut down the road but so far no major disruptions have been reported Tuesday at the airport. The workers are staging a one-day strike to protest the use of non-union contract workers for services such as cabin cleaning and baggage handling.
Also, hundreds of people demanding immigration reform and economic equality have gathered in downtown Los Angeles for a rally.
Black-clad protesters in Seattle used sticks to smash small downtown windows and ran through the streets disrupting traffic.
Meanwhile abroad, under a gray, threatening Madrid sky that reflected the dark national mood, 25-year Adriana Jaime confided she turned out because she speaks three foreign languages and has a masters degree as a translator -- but last worked for what she derided as peanuts in a university research project that was to last three years but was cut to three months. Jaime has been unemployed for six months, and sees her future as grim at best.
"I am here because there is no future for the young people of this country," she said as marchers walked up the city's main north-south boulevard, protesting health care and education spending cuts and other austerity measures. Many carried black and white placards, with the word NO and a pair of red scissors pictured inside the O.
Spanish Prime Minister Mariano Rajoy is trying desperately to cut a bloated deficit, restore investor confidence in Spain's public finances, lower the 24.4 jobless rate, and fend off fears it will join Greece, Ireland and Portugal in needing a bailout.
Ana Lopez, a 44-year-old civil servant, said May Day is sacred for her but this year in particular, arguing the government is doing nothing to help workers and that the economic crisis is benefiting banks.
"Money does not just disappear. It does not fly away. It just changes hands, and now it is with the banks," Lopez said. "And the politicians are puppets of the banks."
In France, tens of thousands of workers, leftists and union leaders marked May Day with glee, hoping that a presidential runoff vote Sunday will put a Socialist -- Francois Hollande -- at the helm for the first time since 1988. Many voters fear Sarkozy will erode France's welfare and worker protections, and see him as too friendly with the rich.
"Sarkozy has allowed himself for too long to manhandle the lower classes," said Dante Leonardi, a 24-year-old in Paris. "Today we must show ... that we want him to leave."
Hollande has promised high taxes on the rich.
"We are going to choose Hollande because we want something else for France. We want to keep our jobs, we want to keep our industrial jobs, we want a new economy," said protester Serge Tanguy.
In debt-crippled Greece, more than 2,000 people marched through central Athens in subdued protests. Minor scuffles broke out in Athens when young men targeted political party stands, destroying two and partially burning another. There were no injuries.
Italian Labor Minister Elsa Fornero insisted on the need to reform labor market laws that make it virtually impossible for employers to fire workers in some situations, discouraging hiring. Because of that gridlock and the lack of work in Italy, she said, "It's not a nice May 1st."
Even in Germany, where the economy is churning and unemployment is at a record low, unions estimated that 400,000 people showed up at over 400 May Day rallies. The DGB union group sharply criticized Europe's treaty enshrining fiscal discipline and the resulting austerity measures across the continent, calling instead for a stimulus program to revive the eurozone's depressed economies.
DGB chief Michael Sommer told thousands of workers in Stuttgart that a "Marshall Plan" worth billions of euros (dollars) was needed to stimulate Europe's economy, the German news agency dapd reported.