NEW YORK (CNN) -- Federal, state and municipal agencies staged an elaborate drill in the waters off New York City on Tuesday to prepare for the possibility of a nuclear or dirty-bomb attack from the water. A U.S. Coast Guard vessel passes a container ship in New York Harbor as part of Tuesday's terror drill. "We're a big city, and there are vulnerabilities," said Ray Kelly, commissioner of the New York Police Department. Agencies involved in Tuesday's test  emphasized they did not undertake it because of a specific threat against the city. However, Kelly said the city was taking no chances after a proclamation years ago by Osama bin Laden. "We do know that Osama bin Laden several years ago obtained a fatwah to use nuclear weapons, and our goal is to make certain that that fatwah does not come to fruition," he said.
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NYPD Commissioner Ray Kelly: "We're a big city, and there are vulnerabilities"
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Participating agencies stressed that the drill was not in response to a specific threat
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Authorities were to decipher sinister intent from any of eight boats in waterway
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They were on lookout for abnormally high concentrations of radioactivity
Eight government agencies participated in the drill, ranging from the @placeholder to the U.S. Coast Guard.