New York City is bracing for nearly one million people to crowd into world famous Times Square for New Year's Eve celebrations, and officials say security forces will be ready.
Police are setting up security checkpoints, sealing entrances to underground pipes and tunnels, and installing scanners to detect radiation and other dangerous chemicals. A network of security cameras also is in place.
Once the festivities begin late Friday, police say they will be using bomb-sniffing dogs to patrol along with uniformed officers and officers on horseback. Counter-terrorism officers will also be present.
New York City Police Commissioner Ray Kelly has said there are no specific threats against the city although officials are aware such celebrations are always a potential target.
Officials say security arrangements are adjusted every year based on the latest intelligence.
U.S. President Barack Obama's chief counter-terrorism advisor has said security officials have increased their efforts to ward off any possible attacks during the period between the Christmas holiday on December 25 and New Year's day on January 1.
John Brennan told reporters last week the ability of terrorists to train and move operatives to carry out large-scale attacks has lessened due to intensive anti-terrorism efforts.
Last year, a young Nigerian man allegedly attempted to bomb a U.S.-bound airliner on Christmas Day with explosives concealed in his underwear.
Visitors have been flocking to New York City's Times Square since 1907 to watch as officials lower a ball to mark the start of the new year.
This year's ball is made of Waterford Crystal. It is more than 3.5 meters wide and weighs nearly 5,400 kilograms.