Manchester United have condemned supporters that sang offensive chants in Thursday's Europa League defeat at Liverpool.
Songs referencing the stadium disasters at Hillsborough and Heysel in the 1980s could be heard during the last-16 first leg at Anfield, in which United were beaten 2-0.
Those responsible have been met with widespread criticism and United have vowed to prevent a recurrence by holding talks with supporter groups.
"It has always been the position of Manchester United that chants of this nature, which refer to historical tragedies, have no place in the game and do not reflect the values the club holds," a United spokesperson said.
"We are in discussion with our fans' groups to seek their support in preventing this type of behaviour in the future."
The second leg takes place at Old Trafford on Thursday.