Anti-Wall Street protesters Wednesday vowed to regroup and carry on their campaign after police cleared Occupy camps in Los Angeles and Philadelphia, detaining nearly 350 people.

The latest evictions followed action in recent weeks against anti-Wall Street encampments in cities across the United States including Dallas, New Orleans, Oakland, Portland, and New York, the cradle of a now-global movement.

But the demonstrators were unbowed, unveiling a plan to shut down major ports along the US West Coast and Canada's Pacific seaboard in a day of action on 12 December.

"We're shutting down these ports because of the union busting and attacks on the working class by the 1 per cent," said Barucha Peller of the West Coast Port Blockade Assembly, of Occupy Oakland, in a statement.

"We are also striking back against the nationally coordinated attack on the Occupy movement. In response to the police violence and camp evictions against the Occupy movement, this is our coordinated response against the 1 percent."

The statement came only hours after some 1,400 Los Angeles police cleared out hundreds from the two-month-old camp in a park outside City Hall, Mayor Antonio Villaraigosa said.

"I couldn't be prouder of what I believe is maybe the finest moment in the history of the LAPD," he said.

"Almost 300 people were arrested with a minimal use of force.... The activists' fundamental rights were respected. This was truly an exemplary operation," he said. A total of 292 protesters were arrested, he added.

The tent settlement in Los Angeles was one of the biggest of many that have sprung up across the country to protest financial inequality, corporate greed and the influence of big business on government.

But Los Angeles protesters remained defiant. "Occupy LA will not die. We will move forward and the Occupy movement will only become stronger as a result of this punitive action," spokesman Mario Brito told reporters.

"We feel the pain of being evicted from what was our home for 60 days, but it does not compare to the pain of millions of Americans who are being evicted from their homes by greedy banks."

In Phoenix, Arizona, police used pepper spray to disperse a group of protesters during an anti-Wall Street rally, arresting six people.

Officers deployed pepper spray at two groups of protesters who apparently tried to break through a police line at an annual meeting of the American Legislative Exchange Summit.

The anti-Wall Street movement, born in New York in mid-September, now finds itself in a precarious position, with permission to camp in public spaces being rapidly curtailed.

"If anything, (the movement) has gotten much stronger," said one protester who identified himself as Joel at the camp just two blocks from the White House in Washington, one of Occupy's few major encampments to avoid eviction so far.

"There's nothing they can do to stop the momentum of this thing," he said.

But the protests have worn thin in many places, including Philadelphia, where a police raid early Wednesday cleared a downtown park of its protesters after the mayor warned of deteriorating health and safety conditions.

Police made 52 arrests there, a police spokeswoman said.

In Los Angeles, the eviction was implemented two days after a midnight Sunday deadline set by the mayor to clear the camp, which had been in place since 1 October.

In both Los Angeles and Philadelphia, the police were followed by garbage trucks, which carted off tents, tarps and signs that had accumulated in the camps.

Minor scuffles broke out in both operations, but the scene was far calmer than in previous raids, including one in Oakland, California last month in which police fired tear gas and clashed with demonstrators.

New York police cleared the tent camp in Manhattan's Zuccotti Park -- the epicenter of the Occupy movement -- earlier this month, and Occupy Wall Street said on its website that it is in "desperate need of housing and transport."

The loosely organized, left-leaning Occupy Wall Street protesters insist they are exercising their freedom of speech in the run-up to November 2012 national elections.