Nine explosions were detonated in Karbala, accompanied by mortar, grenade, and rocket fire, killing over 100 people, while three explosions near the Kadhimiya Shrine in Baghdad killed 58 more. Though the attack involved armed squads, car bombs, and up to a dozen suicide bombers, there was also an explosive-laden vehicle which was intercepted while trying to enter Basra, as were two suicide bombers in Karbala and others in Baghdad who had entered via Syria. The squads armed with rockets and small arms were meant to kill those wounded by the blasts as well as to trap those trying to flee the carnage.
Al-Qaeda, which considers Shia Islam to be heretical, was immediately held responsible for the attack, and it was believed their intent was to cause much more destruction than actually occurred.
Brigadier General Mark Kimmitt, the American commander in Baghdad, initially blamed Abu Musab al-Zarqawi for the attacks, but it was subsequently revealed that Zarqawi's field commander in Iraq,
Abu Abdallah al Hassan Ben Mahmoud , directed the attacks. Ayatollah Ali al-Sistani, a highly influential Shiite in Iraq, blamed the U.S. for allowing the attacks to occur, but Kimmitt had agreed with Shiite leaders to vacate the shrines out of respect for cultural differences.