Violence in Iraq has decreased since its peak in 2006–07, but attacks remain common. Deaths rose in 2012 for the first time in three years. In the months leading up to the 20 April provincial elections, the first since the withdrawal of US forces in 2011, tensions were high in Iraq as Sunni groups claimed they were being marginalized by Prime Minister Nouri al-Maliki's Shiite dominated government. A number of large scale attacks linked to the Sunni umbrella group Islamic State of Iraq were carried out in early 2013 in an attempt to destabilize the country ahead of the elections. At least fourteen election candidates were murdered, while Anbar and Nineveh provinces postponed elections because of security concerns. Four other provinces did not hold elections on 20 April.