Months after the fact, the U.S. coalition has admitted to accidentally killing nearly 40 civilians in the fierce final battle for Mosul. Human rights activists insist the figures are much, much higher.

On Friday, U.S. military officials confirmed 13 incidents that cost the lives of 61 civilians in Iraq and Syria, with 38 of those fatalities from two strikes in Mosul in March, when Iraqi forces were closing in on ISIS in the old part of the city. These strikes are apparently separate from the acknowledged March 17 coalition strike that killed more than 100 civilians.

The numbers add up to a grim tally since the fight against ISIS began in 2014. “It is more likely than not, at least 685 civilians have been unintentionally killed by Coalition strikes since the start of Operation Inherent Resolve,” the coalition’s latest monthly report stated.

“That’s a hefty, 10 percent jump in the overall fatality numbers reported just in one month,” said Chris Woods, director of Airwars.org, which tracks allegations of strikes from eyewitness, press and social media reports.

Airwars believes the total number of civilians killed since coalition strikes began is much higher—more than 5,200, with a higher rate of reports coming in the last few months—up from an average of 30 to 40 allegations a month to more than 200, Woods said.

The coalition says the rise in allegations and reported deaths in Mosul in March is “attributable to the change in location of Iraqi operations against ISIS, not a change in strategy or administrations,” the public affairs office emailed Saturday in response to questions from The Daily Beast. “The month of March 2017 saw the start of ISF [Iraqi security forces] operations in the much more densely packed West Mosul. West Mosul has many more people, is much more densely populated, and the infrastructure is much older and more tightly packed. This is what the rise in allegations is attributable to.”

Of the Airwars’ estimate of 5,200 deaths, the spokesman’s office said, “ The Airwars numbers are based on allegations, not fact.”

Without naming organizations, the office added that “most of our critics do not conduct such detailed assessments and often rely on scant information, which frequently comes from single unreliable sources. Still their claims are printed as fact and rarely questioned,” adding that this is playing into ISIS’s hands by diminishing support for the mission.

Woods and other human rights advocates shrug off such criticism, and say the rising number of allegations raise questions as to whether military commanders are taking President Donald Trump’s pledge to “bomb the hell out of ISIS,” literally.

Senior Pentagon and coalition officials push back against that, but the current coalition commander acknowledged a greater freedom to operate under Trump.

“We don’t get second-guessed a lot,” Operation Inherent Resolve commander Lt. Gen. Stephen Townsend told reporters in his last press conference from the region Thursday. “We don’t get 20 questions with every action that happens on the battlefield and every action that we take,” he added, not mentioning President Barack Obama by name but echoing complaints of military commanders that the Obama administration micromanaged the war from Washington.

But two senior military officials insist that doesn’t mean they’re breaking their own rules of engagement, and in comments to The Daily Beast, many had bristled over Trump’s campaign trail “bomb the hell out of ISIS” comments. They said they avoid civilian casualties, not only because intentionally harming civilians is against the laws of war, but because it makes the locals who survive turn against them and their allies. The officials spoke on condition of anonymity because they did not want to criticise their commander in chief publicly.

“It’s either relaxed rules of engagement or tolerance for more civilian casualties…or as the command says, increased urban fighting, or ISIS using civilians as human shields,” said Micah Zenko, a national security expert who focuses on the use of air power. He said there’s also a rising incidence of reports that the people killed were in a building nearby the targets, possibly indicating the coalition is using larger, more powerful explosives in this final phase of operations.

“The truth is, nobody knows the answer,” Zenko said. “At least, now they are sensitive to it and they are looking for it.”

U.S. Central Command, which oversees the region for the military, even “reached out to Airwars, indicating they would like to get information on where civilian casualty allegations are for more than a year,” Woods said.

Zenko said he did speak to a military official involved in strike planning who said the pace of strikes had picked up so that most were dynamic rather than deliberate strikes—terms of art meaning “on the fly” versus a target that would be studied for several hours or even days in advance. That means the coalition’s in-house “Red Card” team that flags possible civilian casualties doesn’t get a chance to weigh in on the target or the munitions used.

He said CENTCOM has no “pre-strike pause cell” like CENTCOM commander Gen. Joseph Votel once created for the elite counterterrorism unit, the Joint Special Operations Command. The cell was created to examine the ramifications of a strike in advance after a particularly devastating strike in Yemen.

And in the meantime, the pace of casualty reports has accelerated.

“We had always anticipated…that at this stage of the fight with Mosul and then Raqqa under assault that higher civilian casualties were inevitable,” Woods said. “Even so, the actual numbers we are seeing are far higher than expected. Even taking into account the faster tempo of the battle, they do appear to be at greater risks of harm.”

Airwars’ describes itself as an “all-source monitor,” drawing on Iraqis and Syrians, including press releases from local militant groups and social media reports posted by the public.

“If two or more sources are reporting it and it’s not being refuted by anyone locally—and the coalition hit nearby,” it goes on the list of alleged strikes, Woods said from London Friday. That’s how the group whittled down allegations of 21,000 civilian deaths to roughly 5,200.

And there’s possibly worse to come, as coalition allied forces battle the last ISIS fighters to the death in Raqqa, where Airwars has received allegations of up to 800 civilian casualties since the battle for the city began on June 6.

In the latest coalition report, officials only acknowledge two incidents since June 6, in the Raqqa area, which killed four people. The report said the U.S. military investigations team is working through another 455 reports of possible civilian casualties from Airwars and other NGOs, however.

Amnesty International takes issue with the coalition’s methodology, and the paucity of information they release about the daily strikes.

“They do not use site visits nor do they interview victims,” said Amnesty’s London-based crisis coordinator Donatella Rovera in an interview. “But we remain in a situation where the overwhelming majority of reports received are dismissed as being non-credible.” She and her colleagues conducted on-site interviews for their reports on East and West Mosul.

She said they could help investigators like her eliminate possible false reporting by releasing the coordinates after a strike.

“The information is extremely vague, near Raqqa or near Mosul,” she said of the daily strike list. “Once the strike has happened, ISIS knows where it got hit. They know the geographic coordinates so why not release them?”

The new report states that between August 2014 and July 2017, the Coalition conducted a total of 24,160 strikes that included 51,038 separate engagements—and says the total number of reports of possible civilian casualties is 1169. It’s found a bit over 10 percent—164—to be credible.

“The death of civilians weighs heavy on our hearts. We should never seek to deny this or hide the true cost of war,” said Townsend, ahead of the report’s release. “But I say this with full conviction: The responsibility for civilian casualties in Iraq and Syria lies with ISIS.”

Updated Saturday to add comment from the coalition spokeman’s office.