The government insists that it has expelled (to their home countries) over 500 al Qaeda refugees (from Afghanistan and Pakistan). The US insists that those 500 were largely low ranking volunteers or Taliban. In any event, the Iranian government has little control over what the religious conservatives (who control the police, army and courts) do. Moreover, keep in mind that al Qaeda is not very popular with many religious Iranians. In Afghanistan, Pakistan and other Arab countries, al Qaeda has backed violent persecution of Shias. But many senior al Qaeda have long publicly talked of all Moslems uniting to fight the infidels (non-Moslems.) But this attitude is at odds with what often happens when Sunni and Shia communities live close together.