Early in United's 4-0 win at Old Trafford on Saturday, some home fans sang "always the victims" and "it's never your fault."
The taunts came a day after United manager Alex Ferguson urged supporters of both teams to stop the chants that mock the tragedies of Hillsborough and Munich, the darkest episodes in the clubs' histories.
United released a statement saying the club "deplores" the chant and that "the manager has made the club's position very clear on this matter."
It was unclear whether Saturday's chant was in reference to the Hillsborough disaster in 1989, in which 96 Liverpool fans were killed. Documents were released Wednesday revealing new evidence about the tragedy.
Seven United players were among the 21 killed in an air crash in Munich in 1958.