* Movement inspires rallies in numerous cities
* "Anarchists" wear black bandanas in some locations
* Packets of harmless white powder mailed to N.Y. banks
By Atossa Araxia Abrahamian and Emmett Berg
NEW YORK/OAKLAND, Calif., May 1 (Reuters) - Occupy Wall Street protesters smashed windows in Seattle, fled police on scooters through the streets of New York and clashed with officers in Oakland on Tuesday in May Day demonstrations intended to revive their movement against economic injustice.
Many events were peaceful, marked by meditation in public parks and anti-corporate song-and-dance routines in New York.
But police in Oakland, California, called for aid from neighboring cities and deployed a "small amount" of tear gas on raucous demonstrators who threw objects at police and defied an order to disperse.
Black-clad protesters seized the opportunity to radicalize other demonstrations, wearing black bandanas that symbolize an anarchist faction within the largely peaceful Occupy movement.
The more radical elements have taken a forceful role in West Coast cities such as Oakland, where a report by an outside monitor also criticized Oakland police for using "an overwhelming military-type response" to disperse protesters last October.
Inspired by the Arab Spring, the Occupy Wall Street movement captured world attention last year with a campaign decrying the gap between rich and poor and a political system and tax structured tilted toward the wealthiest 1 percent.
In Seattle, some 50 black-clad protesters marched through downtown, carrying black flags on sticks they used to shatter the windows of several stores including a Nike Town outlet and an HSBC bank before police moved them out of the area.
Others smashed windows at a Seattle federal building, and swarms of demonstrators gathered in an open-air plaza.
New York police arrested about 30 people for disorderly conduct and resisting arrest following a series of scuffles throughout the day. At least 12 were arrested in Portland, Oregon, and 10 in Los Angeles.
About 400 New York protesters - most of them wearing black clothes and bandanas - ran onto Broadway as police chased them on scooters.
New York police reported 10 instances of harmless white powder - apparently meant to raise an anthrax scare - being mailed to financial institutions and others, along with a note saying, "Happy May Day ... This is a reminder you are not in control."
Thousands packed New York's Union Square in a festive atmosphere with Rage Against the Machine guitarist Tom Morello leading a sing-along.
"It's definitely a restart for Occupy Wall Street," said Lily Schwarzbaum, 21, who is from New York but studies in Montreal, Canada. "Occupy Wall Street has been very conscious of making it a kick-off."
Occupy Cleveland canceled its events "out of respect for the city" after U.S. authorities announced the arrest of five self-described anarchists in the Cleveland area on suspicion of plotting to blow up a four-lane highway bridge over a national park.
Occupy Cleveland said in a statement the men arrested were associated with their movement but that "they were in no way representing or acting on behalf of Occupy Cleveland" and that the group was committed to non-violent protest.
Although labor unions rejected pleas from leaders of the Occupy movement for a general strike, and demonstrators backed off a pledge to occupy San Francisco's Golden Gate Bridge, activists hailed the day's events as a step forward in the movement that had grown inactive and cash poor since capturing world attention last fall.
"We've been building important alliances and radicalized people in what they're willing to endorse. I mean, we never even used to celebrate May Day. Now look at this," said David Graeber, an anthropologist and author active in the movement.
May Day, also known as International Workers' Day, has long been a day on which the labor movement holds street demonstrations and marches, but less so in the United States than elsewhere around the world.
In San Francisco, a protest by unionized ferry workers worsened the morning rush-hour for Bay Area commuters. Anticipating a one-day walkout by workers, transportation officials suspended ferry service between San Francisco and Marin County to the north, forcing some 3,000 commuters to head into town over the Golden Gate Bridge instead and slowing traffic over the famed span.
About 200 protesters in Portland, Oregon, were "moving" a woman back into her foreclosed house, chanting "welcome home" when she managed to get in through a side door.
Portland Mayor Sam Adams thanked student demonstrators who marched through town and gathered at City Hall, saying, "keep up the great work" and inviting them to use city hall restrooms.