According to Iraqi military sources a US airstrike hammered a military headquarters in the city of Ramadi on Wednesday, killing at least 22 soldiers in a huge “friendly fire” attack.

The Pentagon denied to report, saying they have launched a strike in Anbar, but were sure it didn’t result in any “friendly casualties,” and that it was 20 miles away from the site hit.

Denials from US officials are common, and not always credible. It is hard to imagine, likewise, that the US launched only a single airstrike in the whole Anbar Province in an entire day.

At the same time, ISIS was hitting a large number of sites in Ramadi, which is raising speculation that Iraqi troops may have mistaken an airstrike for an underground tunnel attack.