With the rise of football hooliganism across English football during the 1970s and 1980s , matches between the two clubs brought some minor and major incidents of hooliganism . Since then , the modern game has seen a decrease in violence between the rival supporters and incidents are fairly uncommon . This is more likely due to an increase in Police presence and CCTV with huge steps taken to keep the fans separated . To this day , both sets of fans still hold a resentment toward each other . As well as physical violence , sections of the clubs ' fan bases often taunt each other with unsavoury chants about the Munich air disaster and the Hillsborough disaster respectively
Munich air disaster
Munich air disaster
Liverpool F.C.–Manchester United F.C. rivalry