| Not a public warning but an analytic note to law enforcement officials. This goes along with earlier reports of information suggesting an early Oct attack. |
Authors with the U.S. Office of Intelligence and Analysis added that they have "no credible or specific information that terrorists are planning operations against public buildings in the United States." The FBI and DHS analysts said they were releasing the note because "it is important for local authorities and building owners and operators to be aware of potential attack tactics."
According to the note obtained by NBC News, a "recently discovered audio recording of al-Qa'ida training sessions conducted several years ago provides instruction to potential suicide terrorists on seizing a publicly accessible building and damaging or destroying it with explosive charges."
Among the materials on a CD--ROM seized earlier this year by Belgian authorities and provided to Interpol, the note said, "is a detailed audio explanation by now-deceased senior al-Qa'ida operative Yousef al-Ayeeri of a method taught in an al-Qa'ida training camp for attacking a publicly accessible building. Interpol believes the Arabic-language recording was made shortly before al-Ayeeri's death in 2003."
Saudi security forces killed al-Ayeeri in 2003.
The FBI and DHS said al-Ayeeri's audiotape walks potential suicide bombers through the following scenario: "Once a target is selected, al-Ayeeri recommends assembling a team of 12 individuals, each armed with an assault rife and grenade and carrying approximately 20 kilograms of explosives. The attackers are to storm the building, seal off escape and access points, and occupy it long enough to set and detonate their explosive packages. Al-Ayeeri stressed the importance of carrying out these steps before law enforcement can respond, even if notified early in the attack. He assumes the attackers will be killed during the operation," the FBI note said.
The instructional audiotape continued: "Al-Ayeeri believed attackers would be able to enter many publicly accessible buildings easily with little or no resistance from often poorly trained and lightly armed or unarmed security guards, and that an explosion from inside the building would be particularly effective."
In the unclassified report, the analysts added that, "if each of the 12 attackers' 20 kg charge is combined into a single large bomb, it would have more explosive power than the truck bomb used in the 1983 Beirut Embassy attack. Terrorists to date have not conducted attacks on public buildings using the full range of tactics covered in al-Ayeeri's training."
Since 9-11, the FBI and DHS have issued hundreds of similar warnings and bulletins to law-enforcement officials, cautioning them about potential terrorist attacks. Critics have said that some of the scenarios seem implausible, including warnings about teams of scuba-diving bombers and terrorists' use of prosthetic devices that would allow women to hide explosives in devices "that mimic the look of a pregnant woman." Law enforcement officials have responded that there's a need for aggressive intellience sharing--one of the lessons learned the hard way after the 9-11 terrorist attacks.