The number of civilians slain across Iraq climbed to unprecedented levels in July and August, with 6,599 people killed by violent acts over that time, the United Nations said.
The report on Wednesday from the UN Assistance Mission in Iraq raised new questions about US and Iraqi forces' ability to bring peace to Baghdad, where the bulk of the violent deaths occurred.
It offered a grim assessment of other indicators as well, from unlawful and questionable detentions, to the growth of sectarian militias and death squads, and the rise in "honour killings" of women.
Iraq's government, set up in 2006, is "currently facing a generalised breakdown of law and order which presents a serious challenge to the institutions of Iraq," the report said.
At the heart of the UN findings are the casualty figures that combined two counts: from the Ministry of Health, which records deaths reported by hospitals; and the Medico-Legal Institute in Baghdad, which tallies the unidentified bodies it receives.
According to those two sources, violent civilian deaths in July reached an unprecedented high of 3,590 people, which averages more than 100 a day. The August toll was 3,009 people, the report said.