United's biggest win of the season was marred by a short burst of anti-Liverpool chanting from a small minority of home fans following on from this week's damning report on the handling of the Hillsborough disaster in 1989, in which 96 people died.
The report laid bare a shocking cover-up which attempted to shift the blame for the tragedy on to its victims, revealing that South Yorkshire Police had instructed officers to change or amend their statements relating to the tragic events.
One clearly audible chant at Saturday's game at Old Trafford was "Always the victims, never your fault", believed to be in reference to the report findings.
However, the song has been sung since Liverpool striker Luis Suarez was found guilty of racially abusing United defender Patrice Evra last season, which saw the Uruguay international given an eight-game ban and a fine.
It is understood the Premier League deem the chants to be unacceptable but believe it is a matter for the clubs themselves to deal with.