(WASHINGTON) -- ABC News has learned that the FBI will continue its expanded security effort at least on Monday and perhaps into the coming week until more can be learned about a terrorist plot.
The measures include pressing informants for additional information, reexamining current cases and pursuing suspects who travelled to the U.S. from South Asia in August. The bureau is focused on a relatively narrow pool of men.
The FBI's current list was developed by running names through all terror watchlists and intelligence files available to the U.S. government. The names were narrowed down by age, dates of travel, and travel routes.
The Department of Homeland Security also plans to continue the stepped up security that it began last week. The measures have included placing additional air marshals on flights, increasing the number of heavily armed teams at airports, subways and other mass transit locations. Bomb sniffing dog units and units with radiation detectors will also be out in full force. There will also be more security at federal buildings, with officials extending the perimeters around sensitive areas including water treatment facilities and nuclear power plants. The department continues to urge citizens to report anything suspicious. The mantra: if you see something, say something.
Prior to 2009, many federal officials openly said they did not believe that al-Qaeda necessarily planned for specific dates, but executed attacks when they were ready. Then in late summer in 2009 U.S. government discovered an al-Qaeda plot that was clearly set to be launched just after the 9/11 anniversary. The plot has been forgotten by many, but sources say it was perhaps al-Qaeda’s most sophisticated attempt since 9/11 to attack the U.S. The plan called for a terror cell to detonate backpacks full of homemade explosives on New York subways in the heart of midtown Manhattan. The dates: likely between September 11-14th.
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