Last week, the Syrian Observatory for Human Rights reported a US airstrike against a school in the Syrian town of al-Mansour, saying it killed 33 civilians who were sheltering within. Other NGOs confirmed the incident, with Raqqa Is Being Slaughtered Silently saying as many as 50 civilians were killed.

As is so often the case, this civilian death toll will not be included in the Pentagon’s official count of civilians they’ve killed in airstrikes, as today they declared the incident “not credible,” and Lt. Gen. Stephen Townsend maintained that the attack was “a clean strike.”

Townsend insisted that the US had intelligence that ISIS was using the school, and said that the bodies observed within after destroying it are “what we expected to see.” This contradicts last week’s Pentagon claims that they did not hit the school, but were targeting something sort of “near” the school.

It also contradicts the assessment of both the Observatory and Raqqa Is Being Slaughtered Silently, both groups that are anti-ISIS and would have no reason to make up stories of the US killing a bunch of civilians if they had actually bombed ISIS.

The more reasonable explanation is that the Pentagon is once again sweeping an incident of civilian deaths under the rug, part of an ongoing effort to dismiss killings as “not credible” which has left their official death toll less than 10% the toll from private outlets.