An Internet posting obtained by NBC News — written mostly in Arabic — details how to fire a shoulder-fired missile and how to overcome security measures.
NBC terrorism analyst Evan Kohlmann says it was posted five days ago on an Internet location used by Iraq's top terrorist, Abu Musab al-Zarqawi.
"We've seen plenty of material on radical Islamic Web sites dealing with shooting down military aircraft in combat zones," says Kohlmann. "However, this is the first time I've ever seen the deliberate targeting of civilian aircraft leaving U.S. airports."
NBC News will not reveal many of the details. There's a sketch of a terrorist on a rooftop shooting a missile at a plane, and information on possible evasive tactics. Much of the information appears to have been taken from the Web site of a U.S. magazine. There are also maps showing flight paths and new security perimeters from New York's John F. Kennedy International Airport.
New York officials say they take this seriously and have alerted security at the airport. The FBI is still analyzing the information, but terrorism experts tell us there's no suggestion this poses any immediate threat.
"What concerns me is the acknowledgement by Zarqawi's people that we have vulnerability in our airports, of the launching of missiles against commercial airliners," says Charles Slepian, a risk analysis expert.
Al-Qaida has tried to shoot down a plane. In 2002, terrorists fired missiles at an Israeli airliner in Kenya. And a launcher tube was found near a U.S. airbase in Saudi Arabia.
How tough would it be to pull off an attack in the United States?
"The hardest thing for al-Qaida to do in order to carry out one of these attacks is to smuggle both the shooters and smuggle the weapons into place," says James Chow, an analyst with the Rand Corp. who has authored a study on shoulder-fired missiles.
The Internet posting ends with a provocative message: "This is what I have FOR now. I hope it is useful for my dear brothers."
