Two defectors from Iran's intelligence service testified that Iranian officials had "foreknowledge of the 9/11 attacks." By contrast, the 9/11 Commission "found no evidence that Iran or Hezbollah was aware of the planning for what later became the 9/11 attack. At the time of their travel through Iran, the al Qaeda operatives themselves were probably not aware of the specific details of their future operation." In addition, both bin al-Shibh and Khalid Sheikh Mohammed denied "any relationship between the hijackers and Hezbollah" and "any other reason for the hijackers' travel to Iran" besides "taking advantage of the Iranian practice of not stamping Saudi passports."