Iraqi government figures show that violence in the country killed more than 15,000 civilians and security personnel last year, making it the deadliest year since 2007.
Figures compiled by the health, interior and defense ministries put the death toll at 15,538, compared with 17,956 killed in 2007 at the height of Sunni-Shi'ite sectarian fighting.
Last year's toll was more than double the 6,522 people killed in 2013.
Iraq Body Count, a Britain-based independent group that tracks violence in Iraq, gives an even higher toll for 2014, reporting that 17,073 civilians were killed.
Sectarian violence and the onslaught of the Islamic State jihadist group contributed to the bloodshed.
In a New Year's speech, Iraqi Prime Minister Haider al-Abadi called 2014 the "most difficult and painful of years" for Iraqis because of the attacks carried out by Islamic State. The group now controls wide areas in five Iraqi provinces.
The U.S. military says the U.S.-led coalition conducted 29 air strikes against Islamic State targets on Wednesday, 12 in Iraq and 17 in Syria. A statement said the air strikes destroyed IS-held buildings, fighting positions, checkpoints, tactical units and a mortar system.