Overall, militant attacks in Iraq have dropped to levels not seen since spring 2004, U.S. military spokesman Rear Adm. Patrick Driscoll said this week. Attacks are down 70% since President Bush ordered a U.S. troop increase, or “surge,” early last year.

Al-Sadr agreed to a truce earlier this month after two months of clashes with U.S.-backed Iraqi security forces. The fighting followed a decision by the Iraqi government to rein in al-Sadr’s Mahdi Army and other Shiite militant groups. Iraqi forces have also intensified their offensive against Sunni militants, including al-Qaeda, in the northern city of Mosul.