The United Nations says 1045 people were killed in Iraq during May, in the worst spike in violence since the civil war five years ago.
Tensions are worsening between the Shi'ite leaders of the country and the Sunni minority, who have held months of protests demanding an end to what they perceive as the marginalisation of their sect.
Invigorated by the Sunni revolt in Syria and by Iraqi Sunni Muslim discontent at home, al Qaeda's and other armed groups are regaining ground lost during their fighting with American troops. US forces left in December 2011.
