Figures compiled by the health, interior and defence ministries put the death toll at 15,538, compared with 17,956 killed in 2007, during the height of sectarian killings.

The toll was also more than double the 6,522 people killed in 2013.

in June the so-called Islamic State group spearheaded a major offensive, sweeping security forces aside.

The terrorists overran Iraq's second city Mosul and then they were eventually stopped short, but seized swathes of five provinces north and west of the capital.

A renewed ISIS push in the north in August drove Kurdish forces back towards the capital of their autonomous region, helping to spark a US-led campaign of air strikes against the terrorists.

Iraqi soldiers and police, Kurdish forces, Shiite militias and Sunni tribesmen have succeeded in regaining some ground from IS.

Meanwhile more than 76,000 people were killed in Syria's conflict in 2014, including thousands of children, making it the deadliest year in the nearly four-year war, a monitoring group said Thursday.

The Syrian Observatory for Human Rights said it had documented the deaths of 76,021 people.

Of the total, 17,790 were civilians, including 3,501 children.

Additionally, more than 15,000 rebel fighters were killed, as were nearly 17,000 militants from terrorists groups, including the ISIS and Al-Nusra Front, Al-Qaeda's Syrian affiliate.