NEW YORK (AP) -- Less than two weeks after graduating from the New York City police academy, more than 1,500 rookie officers have a daunting first assignment: helping to protect Times Square on New Year's Eve.

The deployment is just one of an array of security measures - many visible, many not - that the New York Police Department rolls out each year for the event that turns the "Crossroads of the World" into a massive street party that stretches 17 blocks through the heart of Manhattan.

Behind the scenes leading up to New Year's Eve, city police officials meticulously map out how to control crowds that can swell to 1 million. The yearly ritual also means worrying about potential terror threats.

"There will be several thousand police officers involved," Police Commissioner Raymond Kelly said Thursday when asked about security. "I think we do this pretty well. We have a lot of experience in doing it."

Kelly said so far there are no specific threats against Times Square. But in the post-9/11 world, the department knows from experience - especially a botched attempted car bombing in the summer of 2010 - that Times Square is a potential terror target.

Backed by the Pakistani Taliban, Faisal Shahzad left a Nissan Pathfinder outfitted with a crude, homemade propane-and-gasoline bomb on a block teeming with tourists. The explosive malfunctioned, but the near-miss spread a wave of fear across the city.

Shahzad was arrested and, after a guilty plea, sentenced to life in prison. But he warned, "Brace yourselves, because the war with Muslims has just begun."

Since then, the NYPD has maintained a higher profile in Times Square, with mounted police and foot patrols outside hotels, restaurants and Broadway theaters. The department even elevated its neon "New York Police Dept." sign on West 43rd Street several feet so it's more visible.

The usual security is bolstered each New Year's Eve by an army of extra patrol officers who use police barriers to prevent overcrowding and for checkpoints to inspect vehicles, enforce a ban on alcohol and check handbags. Revelers will see bomb-sniffing dogs, heavily armed counter-terrorism teams and NYPD helicopters overhead.

What won't be as evident are the plainclothes officers assigned to blend into the crowd and other officers keeping watch from rooftops. Many officers will be wearing palm-size radiation detectors designed to give off a signal if they detect evidence of a dirty bomb, an explosive intended to spread panic by creating a radioactive cloud.

The bomb squad and another unit specializing in chemical and biological threats will sweep hotels, theaters, construction sites and parking garages. They will also patrol the sprawling Times Square subway station.

The NYPD also will rely on a new network of about 3,000 closed-circuit security cameras carpeting the roughly 1.7 square miles south of Canal Street, the subway system and parts of midtown Manhattan. In recent years, police stationed at high-tech command centers in lower Manhattan began monitoring live feeds of Times Square, the World Trade Center and other sites.

Times Square isn't the only show in town this New Year's Eve - or the only security concern. Police also will be beef up patrols in Central Park, site of a midnight run, and at fireworks displays at the Statue of Liberty.

The NYPD harbor unit will keep an eye on 33 dinner cruises on the city's waterways. Add to the list the Phish concert at Madison Square Garden.

On a smaller scale in outlying neighborhoods, police are concerned about a phenomenon seen in past years: people who ring in the new year by firing guns into the air.

"We urge people not to do that," Kelly said.

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