WASHINGTON—A set of handwritten notes picked up by the Navy SEALs who killed Osama bin Laden prompted the government to warn of potential al Qaeda threats to the U.S. train network, the first known use of intelligence gleaned from the raid.
In an "intelligence message," the Department of Homeland Security alerted law-enforcement officials that initial analysis of evidence seized from bin Laden's compound shows al Qaeda hoped to attack trains in the U.S., possibly on the anniversary of the Sept. 11 attacks.
According to the DHS bulletin, the terror group in early 2010 envisioned sabotaging a railway to cause a wreck. DHS said it isn't clear if there has been any further planning since February 2010. The department didn't offer details on the location or type of train, because the original information was vague, officials said.
The DHS message was prompted by notes discovered in the Abbottabad, Pakistan, compound where bin Laden was killed. According to U.S. officials, the handwritten notes, which were contained in a book, weren't addressed to any particular operative. They were described as "ramblings" and "aspirational" by one Obama administration official. It isn't clear if bin Laden or someone else wrote them.
The notes talked about "attacking America during symbolic times and using mass transit," one administration official said.
Counterterrorism officials said this new threat information was more remarkable for its source—bin Laden—than for its content. The notes showed his personal interest in a railway attack.
"It's the first time we've gotten something directly from him," a U.S. counterterrorism official said. "There was nothing new in it. What's different about it is it was in bin Laden's house."
Al Qaeda and other terror groups have long aspired to blow up commuter trains and subways in the U.S. The Federal Bureau of Investigation in 2009 disrupted a plot to blow up trains in New York City. Washington has also been a target. What alarmed counterterrorism officials this week wasn't the content of the notes, but that they were found in bin Laden's house, said one U.S. counterterrorism official.
The counterterrorism official said the rail-threat information is the first concrete threat intelligence extracted from bin Laden's compound. The official said he was sure more threat information would emerge as more materials from the compound are examined. The U.S. is already in possession of more intelligence, which has yet to be made public, officials say.
While the information was important enough to alert local and private-sector officials, intelligence agencies concluded it "did not warrant an advisory being issued indicating an elevated" threat level, the counterterrorism official said.
"We're continuing to monitor it" the official said of any threat information that would indicate an imminent or more heightened threat to railways.
The Navy SEALs who conducted the bin Laden raid carried off five computers, 10 hard drives and more than 100 storage devices, such as DVDs and removable flash drives, U.S. officials said. The trove has been described by U.S. officials as the largest potential intelligence coup of the post-9/11 era.
A Central Intelligence Agency task force, which has already conducted a preliminary analysis of the material, is hunting for leads on the location of bin Laden's second-in-command, Ayman al-Zawahiri, who is widely expected to ascend to the top of al Qaeda, as well as for information about new plots, names of other terrorists and any information about whether members of the Pakistani government helped conceal bin Laden.
To analyze that data, officials are doing what one described as "scanning the treetops for the most immediate intelligence'' that points to possible imminent threats. Over time, analysts will dig deeper into the information to try to connect different clues and learn more about the inner workings of al Qaeda.
Because vast amounts of information have to be translated, sifting the seized materials will take a long time and threat information will likely come out in dribs and drabs, counterterrorism officials said, predicting it would take weeks just to do a preliminary assessment of the material.
In a written statement, DHS spokesman Matt Chandler said "this alleged Al Qaeda plotting is based on initial reporting, which is often misleading or inaccurate and subject to change." He said the agency will issue a formal alert only when it has "specific or credible" information.