The warnings stretched across two presidential administrations. A newly released collection of presidential intelligence briefs shows warnings spanning the Clinton and George W. Bush administrations, including reports that discussed possible hijackings and the prospect of using an explosives-packed aircraft against a U.S. city. The warnings did not identify the specific targets or timing of the Sept. 11 plot. By August 2001, intelligence officials were also reporting suspicious activity inside the U.S. consistent with preparations for hijackings or other attacks, while the FBI was conducting roughly 70 investigations it considered related to bin Laden. The CIA released 71 intelligence reports on the 25th anniversary of the attacks, offering a new look at the warnings reaching the highest levels of government before nearly 3,000 Americans were killed.