United Nations investigators have concluded that Syrian President Bashar al-Assad’s regime, as well as ISIS militants, carried out chemical attacks in the country in 2014 and 2015. The UN and another group—the Organization for the Prohibition of Chemical Weapons—said Syria used chlorine gas in at least two attacks and that ISIS likely used mustard gas in another. The organizations looked at nine cases in seven towns. Outside of the three confirmed, evidence led investigators to believe the others were legitimate cases in which responsibility simply couldn’t be officially established. U.S. Ambassador to the UN Samantha Power called for action against Assad’s government, saying the findings were no different than the “numerous other confirmed cases of chemical weapons use across Syria, and countless other allegations of such use, including as recently as several weeks ago.” The French ambassador to the UN, Alexis Lamek, said: “When it comes to proliferation, use of chemical weapons, such weapons of mass destruction, we cannot afford being weak and the council will have to act.” The UN Security Council will convene to discuss the issue on Aug. 30.