Suspicion fell on Osama bin Laden and his al-Qaeda organization almost immediately. Known to have harbored hatred for the United States since the basing of U.S. fighters and other military personnel in Saudi Arabia during the first Gulf War, bin Laden has tried "To kill Americans and their allies — civilians and military — is an individual duty for every Muslim who can do it in any country in which it is possible to do it," <ref>[http://awildernessvoice.com/Mohammed.html]</ref>, and often succeeding. In four previous attacks, bin Laden's operatives
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Suspicion fell on Osama bin Laden and his [[Islam|Islamic extremist]] al-Qaeda organization almost immediately. Known to have harbored hatred for the United States since the basing of U.S. fighters and other military personnel in Saudi Arabia during the first Gulf War, bin Laden has tried "To kill Americans and their allies — civilians and military — is an individual duty for every Muslim who can do it in any country in which it is possible to do it," <ref>[http://awildernessvoice.com/Mohammed.html]</ref>, and often succeeding. In four previous attacks, bin Laden's operatives
*killed 6 in a bomb explosion in the first attack on the World Trade Center in 1993;
*killed 6 in a bomb explosion in the first attack on the World Trade Center in 1993;
*killed 19 soldiers in 1996 at a military housing complex in Saudi Arabia;
*killed 19 soldiers in 1996 at a military housing complex in Saudi Arabia;