In February 2006 , the Salafi jihadist organization Tanzim Qaidat al-Jihad fi Bilad al-Rafidayn ( also known as Al-Qaeda in Iraq ) bombed one of the holiest sites in Shi'a Islam - the al-Askari Mosque in Samarra . This set off a wave of Shi'a reprisals against Sunnis followed by Sunni counterattacks . The conflict escalated over the next several months until by 2007 , the National Intelligence Estimate described the situation as having elements of a civil war
bombed
2006 al-Askari mosque bombing
Iraq conflict (2003–present)