Following the 2003 Invasion of Iraq and subsequent fall of Saddam Hussein's regime, the minority Sunni sect, which had previously enjoyed increased benefits under Saddam's rule, now found itself out of power as the Shia majority, suppressed under Saddam, sought to establish power. Such sectarian tensions resulted in a violent insurgency waged by different Sunni and Shia militant groups, such as al-Qaeda in Iraq and the Mahdi Army.