Liverpool were forced to apologise for their fans violently attacking the Real Madrid bus with disgraceful projectile missiles on Wednesday evening.
"We condemn unequivocally the actions that led to Real Madrid’s team bus being damaged during its arrival to Anfield this evening. It is totally unacceptable and shameful behaviour of a few individuals," the English club said in a statement.
"We sincerely apologise to our visitors for any distress caused. We will work together with Merseyside Police to establish the facts and identify those responsible."
Celtic pegged back by FC Midtjylland in UCL qualifier
- Watch this event on Eurosport Player
- Opinion: A good Europa League run should not save Arteta's job
- Man Utd ditch red banners at Old Trafford to improve home form - Solskjaer
A video posted on Instagram showed around a hundred Liverpool fans, some holding flares, booing the arrival of the bus.
A video on Twitter showed a section of the bus's outer window frame had been damaged.
Real hold a 3-1 lead in the tie after winning last week's first leg in the Spanish capital. Like most elite European matches this season, the game is being held without supporters due to coronavirus restrictions.
'Moment of truth' - Ronaldo could return to Man Utd - Euro Papers
'It was unfair' - UEFA ditches away goal rule
'You've got to blame Pep' - Why Guardiola's decisions in final made no sense