Human rights and military monitoring groups on Friday repudiated reports about civilian deaths in the U.S.-led coalition's air war against ISIS, with transparency group Airwars estimating that seven times as many civilians have been killed in air strikes than the military claims.

The organization, which was formed by journalists to track the war, found that 5,961 civilians were killed by air strikes in Iraq and Syria between August 2014 and October 2017.

The official estimate of the Defense Department stands at 801, up from 484 confirmed deaths six months ago, with the government saying it's still assessing hundreds of reports of potential unintended casualties. In total, the U.S. has recorded about 1,800 possible civilian deaths, still far less than Airwars' estimates.

Amnesty International also estimated in July that more than 5,800 non-military deaths in the two countries had resulted from the coalition's actions, and reported that the U.S. has "failed to take effective precautions to protect civilians":

They did air-drop leaflets into IS-controlled areas of the city, instructing civilians to stay away from IS or to hang children's clothes on the roof to mark civilian homes. These warnings, however, took little account of the realities of living under IS. Staying away from IS was impossible for west Mosul residents and fighters would execute anyone caught with a flyer in their hands. Houses with children's clothes on the roof were still hit by air strikes.

The New York Times described the United States' fight against ISIS as "the least transparent war in recent American history" in a report last month, and in an extensive investigation found that U.S. strikes resulted in civilian deaths about 31 times more frequently than the government reported.

ISIS lost control this year of two of its largest cities, Raqqa and Mosul, with U.S.-backed forces claiming those victories. But the U.S. bombing campaign led to extensive bloodshed in those cities' civilian populations, with at least 150 deaths in one district of Mosul and Airwars estimating that 119 children were killed in efforts to overtake Raqqa.

On social media, Amnesty International urged greater transparency in reporting the number of civilian lives lost, and more accountability for the U.S.-led coalition.

Like @airwars, @amnesty's research points to far higher civilian casualties in Raqqa (and Mosul, elsewhere) than @CJTFOIR's monthly reports. Here are our recommendations to improve coalition reporting & accountability for #civcas https://t.co/SikV3Ma1zC pic.twitter.com/2w6wE3gjhc

— amnestypress (@amnestypress) November 30, 2017