Al-Qaida operatives who have been detained for years in Iran have been making their way quietly in and out of the country, raising the prospect that Iran is loosening its grip on the terror group so it can replenish its ranks, former and current U.S. intelligence officials say…

Details about al-Qaida’s movements and U.S. efforts to monitor them were outlined to The Associated Press in more than a dozen interviews with current and former intelligence and counterterrorism officials, most of whom spoke on condition of anonymity because they were not authorized to discuss the matter…

U.S. intelligence officials have tried wiretapping and satellite imagery to watch the men. The CIA even established a highly classified program — code-named RIGOR — to study whether it could track and kill terrorists such as al-Qaida in Iran. Results have been mixed. Monitoring and understanding al-Qaida in Iran remains one of the most difficult jobs in U.S. intelligence…

A major concern among U.S. officials is that this movement foreshadows the release of al-Qaida’s “management council,” including some of al-Qaida’s most dangerous figures.