The September 11 attacks in the United States in 2001 were carried out by 19 hijackers of the militant Islamist terrorist organization al-Qaeda. In the 1990s, al-Qaeda leader Osama bin Laden declared a holy war against the United States, and issued two fatāwā in 1996 and 1998. In these fatāwā, bin Laden sharply criticized the financial contributions of the American government to the Saudi royal family as well as American military intervention in the Arab world.