Sept. 26, 2011— -- The NYPD is capable of shooting down planes in the event of another 9/11-style attack on New York City, Mayor Michael Bloomberg said Monday, but it's unknown exactly what weapons the police have at their disposal, and whether their arsenal includes surface-to-air missiles.
"The NYPD has lots of capabilities that you don't know about and you won't know about," Bloomberg told reporters Monday, echoing recent comments by police commissioner Ray Kelly.
"Do you mean to say that the NYPD has the means to take down an aircraft?" Kelly was asked by "60 Minutes" on Sunday .
"Yes," he replied, "I prefer not to get into details, but obviously, this would be in a very extreme situation."
It would have to be an extreme situation, given the danger of shooting down a large plane over a heavily populated area like New York City. It's also not entirely clear legally, whether cops -- unlike the military -- could shoot at an unarmed jet.
Neither Bloomberg nor Kelly would specify what weapons the NYPD has its disposal. Many believe New York's top cop was referring to the helicopter-mounted Barrett .50 caliber rifle, known since 2005 to be in the city's counter-terrorism arsenal.
The Barrett, a high-powered sniper rifle, could easily disable a car, truck or small plane, and is often used by the Coast Guard to stop boats carrying drugs, but it likely could not take down a large commercial passenger jet, like those flown into the World Trade Center on September 11, 2001.
To shoot down a large jet, the NYPD would almost certainly need to use a missile or a large caliber machine gun. The NYPD would not confirm to ABC News, which weapons Bloomberg and Kelly were referring to, or were in the city's arsenal.
Bloomberg said there was "not any one technology, not any one weapon" that the city would rely on completely in the event of an air attack.
"The main thing that keeps us safe is the 55,000 people who work for the police department," he said. "The 1,000 dedicated to intelligence and counterterrorism. The 35,000 who are uniformed and on the street every day." The mayor added that the city spends $8.5 billion on policing annually.
During the 9/11 attacks, U.S. Air Force jets were scrambled, but they required the approval of the president to fire. Requests for comment on who is currently empowered to authorize a shootdown if New York City faced an imminent threat were not immediately answered by the NYPD.
In the ten years since 9/11 the NYPD has made counter-terrorism a top priority, taking into its own hands operations that were once solely within the purview of the federal government, including gathering intelligence overseas and acquiring military-grade weapons.
Lower Manhattan today is carefully watched 24-hours a day by a $150 million network of some 1,000 closed-circuit cameras, and another 2,000 are expected to soon dot other parts of the city.