The U.S. State Department has condemned Wednesday’s airstrike on a Doctors Without Borders-supported hospital in Syria. The organization says the airstrike killed at least 50 people, including doctors, nurses and patients. On Thursday, State Department spokesperson John Kirby said the airstrike was likely carried out by the Syrian regime.

John Kirby: “We obviously find this attack reprehensible in every possible way. We’re looking at dozens, if not several dozens, of casualties in this strike on what was clear that was a medical facility. The details and the circumstances of the attack are still coming in, but it sure bears all the hallmarks of the kinds of strikes that the regime has done in the past on treatment facilities and, frankly, on first responders.”