The government denies that it is allowing Iraqi anti-coalition fighters to maintain camps in Iran. Since few of the attacks on coalition forces in Iraq are in Shia areas, it seems unlikely that Iran would harbor Sunni Arab groups. But al Qaeda is another matter. The government is known to hold dozens of senior al Qaeda members, and refuses to extradite them back to their own countries. Saudi Arabia is particularly eager to get it's citizens who are known al Qaeda members and believed to be in Iran.