Casualty figures released by the United Nations mission in Baghdad suggest 1,057 Iraqis were killed in July, which was the most violent month in years.
At least 4,137 civilians have been killed and 9,865 injured so far this year, with Baghdad province worst hit.
“The impact of violence on civilians remains disturbingly high,” UN Iraq representative Gyorgy Busztin said.
“Iraq’s political leaders must take immediate and decisive action to stop the senseless bloodshed,” he warned.
A wave of violence has swept Iraq in the last six months. In July there was a series of bombings in streets, cafes and mosques. Militants also broke into two prisons, setting inmates free.
Mr Busztin – who is in Baghdad as acting special representative for the UN Secretary General, Ban Ki-moon – said the toll for July was the most serious for more than five years.
He characterised the earlier period – the peak of the anti-US insurgency in 2006-07 – as one filled with the “blind rage of sectarian strife”.