Escalating US airstrikes are taking a growing toll on the population of the Syrian city of Raqqa, the de facto capital of ISIS which is presently being invaded by US-backed forces. Reports out of the area are that at least 100 civilians have been killed in US-led airstrikes in a 48 hour span from Sunday to Tuesday.

Monday’s airstrikes were the deadliest incident of that span, with 55 civilians killed in two of the city’s eastern neighborhoods, including at least 19 children. The attacks, according to the Syrian Observatory for Human Rights, hit a particularly densely populated area.

“These are buildings full of civilians that are trying to get away from the front lines,” the Observatory’s director noted, adding that US-led coalition airstrikes seem to be targeting any building with any hint of ISIS activity in the city.

The appears to be a recurrence of the same problem that plagued the later months of the Iraqi invasion of Mosul, where US warplanes caused massive civilian tolls by attacking buildings they claimed ISIS was forcing civilians into, but which in practice were densely populated by locals because they were the only buildings still standing that were seemingly out of the direct line of fire.

Yet in the ever-escalating US war against ISIS, no building, no matter how civilian in nature, is ever really out of the direct line of fire. Such large civilian death tolls have severely harmed morale of forces on the ground, and fueled outcry from human rights groups. Officially, however, the Pentagon’s figures on how many civilians they killed are rarely more than 10% of the actual toll documented by independent NGOs, which so far has allowed the Pentagon to dismiss calls to stop targeting civilians.