Five years after the Sept. 11 attacks, investigators are still looking into the U.S. government's response to the hijackings, specifically to determine why aviation and military officials inaccurately reported their performance on that day.

The Defense Department inspector general will soon release a report into whether the military's testimony to the Sept. 11 commission was "knowingly false," Pentagon spokesman Lt. Col. Brian Maka said Thursday.

The counterpart office at the Transportation Department has completed and is writing a report on whether Federal Aviation Administration officials misspoke in their testimony, said David Barnes, the inspector general's spokesman.

Sept. 11 panel members have said that timelines on the tapes did not match accounts given in testimony by government officials and have asked for the two investigations.

The FAA and defense officials have corrected some information originally given to the panel, such as the exact times the FAA notified the military of the hijackings and the military's assertion that it was tracking one of the planes and intended to intercept it when, in fact, the plane had already crashed.

Meanwhile, newly disclosed tapes made by the military that day confirm again that there was widespread confusion on the morning of the attacks as military fighter jets were scrambled and aviation and defense officials tried to identify the hijacked planes and figure out how to counter them.

The tapes recorded at the North American Aerospace Defense Command (NORAD) were the basis for an article in the new edition of Vanity Fair magazine by Michael Bronner, an associate producer on the movie "United 93."

The Pentagon gave Bronner 30 hours of tapes. They had previously been given to the Sept. 11 panel, though only parts of them were revealed publicly.