From Sahih Muslim (Hadith 7304):
Abu Huraira reported Allah's Messenger (ﷺ) as saying:The world would not come to an end until a day would come to the people on which the murderer would not know as to why he has killed and the slain would not know as to why he has been murdered. It would be said: Why would It happen? To which he replied: It would be because of general massacre and bloodshed. And the slaughterers and the slain would be in Fire, and in the narration of Ibn Aban, the name of Abu Isma'il has been mentioned
Reference: Muslim 7304