NEW YORK – During the first two months of the nationwide Occupy protests, the movement that is demanding more out of the wealthiest Americans cost local taxpayers at least $13 million in police overtime and other municipal services, according to a survey by The Associated Press.

The heaviest financial burden has fallen upon law enforcement agencies tasked with monitoring marches and evicting protesters from outdoor camps. And the steepest costs by far piled up in New York City and Oakland, Calif., where police clashed with protesters on several occasions.

The AP gathered figures from government agencies in 18 cities with active protests and focused on costs through Nov. 15, the day protesters were evicted from New York City’s Zuccotti Park, where the protests began Sept. 17 before spreading nationwide. The survey did not attempt to tally the price of all protests but provides a glimpse of costs to cities large and small.

Broken down city by city, the numbers are more or less in line with the cost of policing major public events and emergencies. In Los Angeles, for example, the Michael Jackson memorial concert cost the city $1.4 million. And Atlanta spent several million dollars after a major snow and ice storm this year.

But the price of the protests is rising by the day — along with taxpayer ire in some places.

“What is their real agenda?” asked Rodger Mawhinney as he watched police remove an encampment outside his apartment complex in downtown Oakland. “I’ve gone up and asked them, ‘What are you truly trying to accomplish?’ I’m still waiting for an answer.”

The Occupy movement has intentionally never clarified its policy objectives, relying instead on a broad message opposing corporate excess and income inequality. Aside from policing, cleaning and repairing property at dozens of 24-hour encampments, cities have had to monitor frequent rallies and protests.

The spending comes as cash-strapped police departments have cut overtime budgets, travel and training to respond to the recession. Nonetheless, city officials say they have no choice but to bring in extra officers or hold officers past their shifts to handle gatherings and marches in a way that protects free speech rights and public safety.

Protesters blame excessive police presence for the high costs in some places. And they note the cost has been minimal in other cities, and worth the spending because they have raised awareness about what they call corporate greed and the growing inequality between rich and poor.

“We’re here fighting corporate greed and they’re worried about a lawn?” said Clark Davis of Occupy Los Angeles, where the city estimates that property damage to a park has been $200,000.

In Oakland, where protesters temporarily forced the shutdown of a major port, the city has spent more than $2.4 million responding to the protests. The cash-strapped city, which had to close a $58 million budget gap this year, was already facing an uphill battle when Occupy Oakland began Oct. 10.

“The cost of the encampments is growing and putting a strain on our already fragile resources — police, public works, and other city staff,” said Mayor Jean Quan.

In New York City, the police department has spent $7 million in overtime on the protests. But that’s small change given the department’s $4.5 billion budget, which allots money for emergency overtime. Last year, the NYPD spent about $550 million on overtime.

“Public safety and providing essential services is what we do. So the first thing we’re going to do is handle the situation, and any situation that comes up,” Deputy Mayor Cas Holloway said. “So yes, this has been significant and it’s been going on for many days, but really in the broad scheme of things, it’s not something that we aren’t prepared to deal with.”

Pete Dutro, a protester in charge of finances in New York City, called the NYPD’s response “completely unnecessary.”

“It’s $7 million of taxpayers’ money that’s being spent to stifle our First Amendment rights,” he said. “You know, they’ve consistently overreacted.”

Other cities were not too concerned about mounting costs, with officials saying they budget for events like these.

Costs were far lower in Boston than City Council President Stephen Murphy initially predicted last month, when he said police costs for providing security at Occupy Boston for October would be as high as $2 million, based on what a police commander at the scene of mass arrests told him.

The city of Boston has spent $575,000 in overtime through mid-November to pay officers policing Occupy Boston. That’s about 2 percent of this year’s $30 million police overtime budget.

“We have a history of starting, as well as managing, historic demonstrations,” said City Councilor Michael Ross. “We’ve done it well and we’ve managed it well, and that’s not going to stop anytime soon, and that doesn’t cease to exist after it hits a certain budget threshold.”

St. Louis; Des Moines, Iowa; Providence, R.I.; and Burlington, Vt., were among the cities surveyed by AP that reported costs of less than $10,000.

But the costs are mounting.

Unlike a parade or a one-day march, the Occupy protests are in their third month in some cities and show no signs of easing up, said Chuck Wexler, executive director of the Police Executive Research Forum, a think tank for police chiefs.

“You’re dealing with 50 to 75 cities where this is going on. In some cities it’s a minimal expense. In some cities, it’s considerable,” he said. “For a city that has slashed overtime, this has an impact. And that means they are going to have to cut back in other ways.”