Violence and military operations claimed the lives of more than 16,000 civilians in Iraq last year, a research group that tracks civilian deaths in Iraq said Thursday, making it one of the deadliest years for war-weary Iraqis since the 2003 U.S.-led invasion.
 
In its annual report, the London-based Iraqi Body Count reported that 16,361 civilian Iraqis died in 2016, with the northern province of Nineveh the worst hit at 7,431 people killed. The Iraqi capital, Baghdad, was next with 3,714 civilians killed, the research showed.
 
Nineveh's capital Mosul and surrounding areas fell into the hands of the Islamic State group in mid-2014 during an onslaught that ended with the seizure of territory in northern and western Iraq. Iraqi troops have since dislodged IS militants from major areas in a massive military operation that started in mid-October.
 
Comparatively, in 2015 17,578 people were killed and in 2014, 20,218 were killed, the report noted.
 
The group considers five broad cause-of-death categories: executions by militants; suicide attacks; bomb explosions; gunfire not involving execution, and air attacks and shelling. Last year, the greatest causes of death were execution and gunfire, which accounted for more than half of all civilian deaths, it said.
 
Iraqi Body Count, which began documenting civilian deaths in Iraq after 2003, compiles reports from media outlets, non-governmental organizations and Iraqi government sources.
 
The report comes only days after the United Nations in Iraq released a report that found 6,878 civilians were killed by violence in 2016. But the U.N. Assistance Mission for Iraq, known as UNAMI, said the numbers didn't include casualties among civilians in Iraq's western Anbar province for the months of May, July, August and December. It said it was hindered from verifying casualty numbers in conflict areas and those killed from secondary effects of violence.
 
The deadliest IS attack came in July, when a massive suicide bombing in a bustling market area in central Baghdad killed almost 300 people, the bloodiest single attack in the capital in 13 years of war. (AP)