It is narrated from Hazrat Abu Huraira (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: Knowledge will be taken away, tribulations will appear, and killing will become widespread. The companions (may Allah be pleased with them) asked, "O Messenger of Allah (peace and blessings be upon him), what is meant by killing?" The Noble Prophet (peace and blessings be upon him) replied: Killing, killing.