The Syrian government continues to deny carrying out the chemical attack in Ghouta last month that has sparked the U.S. threat of military strikes. On Tuesday, Human Rights Watch released the findings of its initial probe into the Ghouta attack. The group’s U.N. director, Philippe Bolopion, said the available evidence strongly points to Syrian government responsibility.

Philippe Bolopion: “We looked at satellite pictures of where the different attacks took place. We looked at a lot of videos that we authenticated first. We talked to doctors who were responding to the scene. We talked to some of the witnesses, who told us where the shells were coming from. And so, when you take all these elements and you look at them very closely, there is only one theory that emerges clearly, which is that most likely it’s the Syrian government that’s responsible for the attack.”

In a new report out today, a United Nations panel investigating human rights abuses in the Syrian conflict accuses both sides of war crimes. Investigators say they have confirmed at least eight massacres committed by Assad regime forces and one by rebels over the past year and a half.