French President François Hollande declared Friday's attacks in and near Paris to be an act of war, and he specifically blamed ISIS.
"It is an act of war that was waged by a terrorist army, a jihadist army, by Daesh, against France," Hollande said in a national address. Daesh is the French government's preferred term for the Islamic state. ISIS has claimed responsibility for the attacks, but Hollande didn't say how the French had confirmed those claims.
Hollande said that ISIS had declared a war "against the values we uphold throughout the world, against who we are. It's an act of war which was prepared, organized, planned from the outside with help from the inside."
He described it as an "act of total savagery," and said that 127 people lay dead. Hollande has issued a decree for three days of national mourning over the attacks.