On December 25, 2006, the United States arrested at least four senior military officials on their visit to Baghdad. It has been mentioned that the Iranians have been arrested after US soldiers raided the compound of Shiite leader Abdul Aziz al-Hakim, leader of the influential Shiite Supreme Council for Islamic Revolution in Iraq (SCIRI). President of Iraq Talabani, a strong US ally, has asked for their release. Hiwa Othman, Talabani's media adviser, told Reuters: "The president is unhappy. He is talking to the Americans about it as we speak." Othman said the Iranian diplomats came to Iraq at the invitation of the Iraqi leader but he was not aware if they had met with him."The invitation was within the framework of an agreement between Iran and Iraq to improve the security situation." Finally, it seems that they have been released on 30 December. One of the commanders, identified by officials simply as Chizari, was the third-highest-ranking official of the Iranian Revolutionary Guards' al-Quds Brigade, the unit most active in aiding, arming and training groups outside Iran, including Hezbollah and Islamic Jihad, U.S. officials said.