Manchester United have condemned the behaviour of fans who sang offensive chants about the Hillsborough Disaster at Liverpool on Tuesday as "completely unacceptable".
Video footage has emerged of a section of United fans taunting their rivals over the tragedy that claimed 97 lives in 1989 during their 4-0 defeat at Anfield.
United have said they will seek to educate fans.
A club spokesperson said: "Manchester United stands in solidarity with Liverpool FC and its fans in remembering the victims of the Hillsborough Disaster. Offensive chants about the tragedy are completely unacceptable and we will work with our supporters' groups to educate fans on the issue."
The chants came after Liverpool fans had joined in with a minute's support for United forward Cristiano Ronaldo, who was absent from the game following the death of his new-born child, as they sang their anthem 'You'll Never Walk Alone'.
The unsavoury scenes, and subsequent apology, come just days after Manchester City were forced to apologise after their fans sang during a minute's silence ahead of the FA Cup semi-final on Saturday.
Last January Shrewsbury Town banned two people from all games for a total of eight years following events at their FA Cup clash with Liverpool.
Video clips emerged after the third-round tie at Anfield on appearing to show some Shrewsbury supporters singing a song about the Hillsborough disaster.
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