The US spent months battling ISIS in Mosul. At least 9,000 civilians were killed in the crossfire.

The US has declared victory in its fight against ISIS, with American allies retaking the last of the group’s major strongholds in Iraq and Syria. But lost amid the celebration is an incredibly grim reality: huge numbers of civilians have been killed in the crossfire.

The latest evidence comes from Mosul, Iraq’s second-largest city, which the US-led coalition battling ISIS retook back in July. A dispiriting report from the Associated Press estimates that between 9,000 and 11,000 civilians died in the battle to free Mosul — a number nearly 10 times higher than previously thought.

According to the report, US-led coalition forces or Iraqi forces were responsible for at least 3,200 civilian casualties over the course of the nine-month battle, which stretched from October 2016 to July 2017. ISIS was responsible for roughly the same number, and it wasn’t clear which side was responsible for the remaining civilian deaths.

Daoud Salem Mahmoud, a Mosul resident who has recovered hundreds of bodies from his old neighborhood, told the AP the war had “turned Mosul into a graveyard.”

The new estimate of civilian casualties from the fight for Mosul comes from data collected by the Iraqi city’s morgue workers, grave diggers, and other residents who have volunteered to retrieve bodies. It also incorporates data from the UN, Amnesty International, Iraq Bodycount, and Airwars, an independent organization that monitors civilian casualties in Iraq, Syria, and Libya.

The figures notably don’t come from the US military itself, which has claimed that months of airstrikes left only a few hundred civilians dead inside Mosul, according to the report.

“It is simply irresponsible to focus criticism on inadvertent casualties caused by the Coalition’s war to defeat ISIS,” Col. Thomas Veale, a spokesperson for the coalition, told the AP.

It’s not the first time the US government appears to have underestimated civilian casualties in the war against ISIS.

The Pentagon claims its air war against ISIS is one of the most accurate in history, and that it is so careful in who it targets that the 14,000 US airstrikes in Iraq have killed just 89 civilians.

But in November, an 18-month investigation by the New York Times found that the US-led military coalition was killing civilians in Iraq at a rate 31 times higher than it has acknowledged.

“In terms of civilian deaths, this may be the least transparent war in recent American history,” New York Times reporters Azmat Khan and Anand Gopal wrote.

The new numbers from Mosul will be pushing that death toll even higher: According to the Associated Press, there are could be hundreds of other dead civilians in unmarked graves around Mosul.

Editor’s Note: After publication, the US Coalition to Defeat ISIS responded to a reporter’s questions with a statement questioning the veracity and statistics of the Associated Press report, saying: “There is no basis for the AP’s claim that one-third of the civilians who died during the battle of Mosul were killed by Coalition airstrikes.” They added that the Coalition has done “everything within its power to limit harm to non-combatants and civilian infrastructure.”