Washington (CNN) -- As details emerged about a possible attack on the 10th anniversary of 9/11, President Barack Obama was scheduled Friday to meet the men responsible for collecting the intelligence during a raid on Osama bin Laden's compound.
The president was to meet with members of the Navy SEAL team involved in the operation, the latest in a series of events for Obama that included a stop at ground zero since he told the world that U.S. Special Forces killed bin Laden.
A senior administration official told CNN the meeting between Obama and members of SEAL Team Six would take place at Fort Campbell, Kentucky. The official, speaking on condition of anonymity, said it would be a private meeting.
The meeting comes a day after a nationwide alert was issued regarding rail security, the first terror threat notification linked to materials found during the raid on the Abbottabad compound in Pakistan. The terror plot was planned for the anniversary of September 11, 2001.
As early as February 2010, al Qaeda members discussed a plan to derail trains in the United States by placing obstructions on tracks over bridges and valleys, the alert said, according to one law enforcement official.
The plan was to be executed later this year, coinciding with the 10th anniversary of the September 11 attacks, though no specific rail system was identified, the official said.
The Department of Homeland Security confirmed the notice went out to federal, state, local and tribal authorities. Spokesman Matt Chandler stressed that "this alleged al Qaeda plotting is based on initial reporting, which is often misleading or inaccurate and subject to change."
"We have no information of any imminent terrorist threat to the U.S. rail sector, but wanted to make our partners aware of the alleged plotting; it is unclear if any further planning has been conducted since February of last year," Chandler said.
Rail agencies across the country were taking no chances.
The Chicago Transit Authority re-issued security bulletins, "reminding employees of what activities to look for and what steps to take should they encounter any suspicious or criminal activity during the course of their duties," said Wanda Taylor, a CTA spokeswoman.
Amtrak employees also were on a heightened "state of vigilance," said spokesman Marc Magliari.
A U.S. official said that "valuable information has been gleaned already" from the cache gathered at bin Laden's compound, though no specific plots or terrorist suspects were identified.
But the material suggests that al Qaeda was particularly interested in striking Washington, New York, Los Angeles and Chicago, according to the law enforcement official who spoke on condition of anonymity.
U.S. authorities have found that al Qaeda appears especially interested in striking on significant dates like July 4, Christmas and the opening day of the United Nations.
The cache included audio and video equipment, suggesting bin Laden may have taped makeshift messages there, a U.S. official said.
Ten hard drives, five computers and more than 100 storage devices, such as disks and thumb drives, were also found, a senior U.S. official told CNN.
In addition to meeting with members of the SEAL team Friday at Fort Campbell, which is home to the 160th Special Operations Aviation Regiment -- the group that operated the helicopters used in the raid on bin Laden's compound, the president will address troops who recently returned from combat in Afghanistan.
With bin Laden's death, there has been a growing call among some lawmakers to immediately withdraw the 130,000 U.S. and allied troops still battling the late al Qaeda leader's followers and his Taliban allies.
Obama has repeatedly said he is confident the United States can meet a self-imposed deadline to begin bringing troops back home in July without compromising Afghan security, though military commanders and government officials have raised concern about the readiness of Afghan security forces.
Lawmakers also have started questioning the U.S. relationship with Pakistan.
During a Senate Foreign Relations committee hearing Thursday, legislators on both sides of the aisle said a new approach to Pakistan was now needed.
Pakistan's government is "very irrational," said Sen. Bob Corker, a Tennessee Republican.
But Pakistani Foreign Secretary Salman Bashir said it is a "false charge" to assert that Pakistani authorities did not go after bin Laden.
He said his country's intelligence agency alerted the U.S. about the presence of al Qaeda operatives in Abbottabad as early as 2004.
Pakistani armed forces chiefs issued a statement Thursday admitting that there had been "shortcomings in developing intelligence" on the terror leader's presence in the country.
The army chief of staff, Gen. Ashfaq Parvez Kayani, also "made it very clear that any similar action, violating the sovereignty of Pakistan, will warrant a review on the level of military/intelligence cooperation with the United States," the statement said.
Pakistan has ordered U.S. military personnel on its territory drawn down to the "minimum essential" level in the wake of the raid, the statement said.
Anti-U.S. sentiment was growing in Abbottabad, where about 600 demonstrators gathered Friday at a rally, chanting "Go America, go America, your show is over."
Some at the rally did not believe U.S. claims that bin Laden was killed in the house, saying that the men killed during the raid were Pakistani nationals.
Meanwhile, the U.N. Commission on Human Rights called on the U.S. to disclose details surrounding the killing of bin Laden.
"In respect of the recent use of deadly force against Osama bin Laden, the United States of America should disclose the supporting facts to allow an assessment in terms of international human rights law standards," the commission's special investigators, Christof Heyns and Martin Scheinin, said in a joint statement.
"For instance, it will be particularly important to know if the planning of the mission allowed an effort to capture bin Laden."
CNN's Jeanne Meserve, Samson Desta, Barbara Starr and Elise Labott contributed to this report.