The Messenger of Allah ﷺ said, "Before the Hour there will come days in which knowledge will be taken away, ignorance will descend, and harj will increase." Harj means killing.
قال رسول الله ﷺ: إن بين يدي الساعة أياما يرفع فيها العلم، وينزل فيها الجهل، ويكثر فيها الهرج، والهرج القتل-
Bukhari related it in the Book of Tribulations (7062), and Muslim in the Book of Knowledge (2672), both through Amash, from Abu Waail Shaqiq bin Salama, who said, "I was sitting with Abdullah and Abu Musa, and they both said" (and he mentioned it).