syria
REUTERS/Goran Tomasevic
The U.S. Treasury Department has accused Tehran of allowing senior al Qaeda members in Iran to move Sunni fighters into Syria, Jay Soloman of The Wall Street Journal reports.
Earlier this month, U.S. officials told Al Jazeera that senior al Qaeda operative Yasin al Suri — who is suspected of moving money and operatives into Syria since 2011 — is now running operations from Iran with the tacit blessing of the government.
The latest charge by Obama administration provides further evidence that parts of the Islamic Republic's government or military have been at least indirectly enabling the rise of extremists in Syria while also serving as Syrian President Bashar al-Assad's closest military and diplomatic ally.
Iran denies the allegations.
From WSJ:
The Treasury sanctioned a senior Uzbek member of al Qaeda, Jafar al-Uzbeki, for allegedly using Iran to move fighters into Syria. The U.S. said Mr. Jafar is part of an al Qaeda network operating from Iran that has also moved fighters into Pakistan and Afghanistan "and operates there with the knowledge of Iranian authorities." 
The Treasury added that the network "also uses Iran as a transit point for moving funding and foreign fighters through Turkey to support al Qaeda-affiliated elements inside Syria," including the main al Qaeda affiliate Jabhat al-Nusra.
Turkey has harbored al Qaeda financiers and allowed many extremists to pass from its territory into Syria over the course of the war.
Al Monitor reports that about a month ago, a high-ranking delegation from Iran visited met high-ranking Turkish officials, including Prime Minister Recep Tayyip Erdogan, in Ankara and "there was agreement on exchanging information and coordinating closely on the situation in Syria."
The Nusra Front and more recently Islamic State of Iraq and al-Sham (ISIS) have been selling oil to the Assad regimeISIS, the most extreme rebel faction in Syria, is dominated by foreigners. Activists claim that one ISIS leader who was captured in Aleppo held an Iranian passport.