FBI warns of shoulder-fired missiles threat

FIM-92 Stinger missile was initially deployed as a man-portable weapon by the U.S. Army.

WASHINGTON (CNN) -- Although it has had no specific warnings, the FBI is alerting law enforcement agencies to be on the lookout for any signs of terrorist plans to use shoulder-fired missiles against U.S. targets, especially commercial airliners.

The alert comes after investigators concluded al Qaeda operatives might have tried to shoot down a U.S. military plane in Saudi Arabia earlier this month.

The FBI warning stressed the United States had no specific intelligence that al Qaeda is planning an attack using shoulder-fired missiles.

CNN NewsPass VIDEO CNN's Jamie McIntyre says an empty launcher found outside a Saudi air base has raised fears that terrorists may target U.S. aircraft (May 30) Play video   Specifications FIM-92A Stinger Missile Short-range, IR shoulder-fired missile Length: 5 ft Launch weight: 10.1 kg Body diameter: 2.75 in Speed: 2,445 ft/sec Maximum range: 3 mi Maxium altitude: 12,464 ft Warhead: Penetrating high-explosive Impact: Fuze Propulsion: Solid propellant Range: 4.5 km Sources: Jane's and Periscope/USNI Military

"The FBI possesses no information indicating that al Qaeda is planning to use 'Stinger' missiles or any type of MANPAD [portable anti-aircraft] weapons system against commercial aircraft in the United States," the warning said.

"However, given al Qaeda's demonstrated objective to target the U.S. airline industry, its access to U.S. and Russian-made MANPAD systems, and recent apparent targeting of U.S.-led military forces in Saudi Arabia, law enforcement agencies in the United States should remain alert to potential use of MANPADs against U.S. aircraft."

On May 10th, CNN first reported the discovery of a tube that could have been used to launch a shoulder-fired surface-to-air missile. The unit was found by a Saudi security patrol inside a fence at the Prince Sultan Air Base, but at that time military officials told CNN it was unclear if the Russian-made SA-7 missile had been fired in an attempt to shoot down a U.S. plane.

But a May 22, 2002 FBI "intelligence bulletin" -- obtained Thursday by CNN -- says, "Subsequent investigation suggests that the discovery is likely related to al Qaeda targeting efforts against U.S.-led forces on the Arabian Peninsula."

Blast marks indicated there may have been an attempt to launch it, but the cover of the tube was still intact, indicating the missile did not fire or perhaps misfired.

The missile tube was found a few miles from where U.S. planes take off and land at the remote desert base, within range of shoulder-fired missiles -- typically specified as up to 3.5 miles (5.6 kilometers) and 13,000 feet (3,963 meters).