According to the U.S. government, 13 of the 19 hijackers entered the United States between April 23 and June 29, 2001. And 11 of those late-arrivers — who were Saudi citizens and primarily the "muscle" for the hijackings — went through Dubai, according to the report.

The hijackers traveled in groups of two or three, taking off from Dubai and arriving at airports in Miami, Orlando, or New York City, the report said.

"As for the money trail, Bin Laden's alleged financial manager, Mustafa Ahmed al-Hisawi, received at a Dubai bank a transfer of $15,000 two days before the Sept. 11 attacks and then left the Emirates for Pakistan, where he was arrested last year.

Marwan Al-Shehhi, an Emirates citizen and one of the hijackers, received $100,000 via the United Arab Emirates. Another hijacker, Fayez Banihammad, also was from the Emirates.

About half of the $250,000 spent on the attacks was wired to al-Qaeda terrorists in the United States from Dubai banks, authorities said. al-Qaeda money in Dubai banks also has been linked to the 1998 U.S. Embassy bombings in Kenya and Tanzania." From USA Today