Liverpool have condemned the smashing of a window in a Real Madrid team coach and apologised for any distress caused.
A club spokesman said the behaviour “of a few individuals” was “totally unacceptable and shameful”.
Hundreds of fans lined Anfield Road, very few wearing masks or observing social distancing, to greet both teams as they arrived for the Champions League quarter-final second leg with a number setting off flares and smoke cannisters.
When one of Real’s buses parked up at the Kop end of the ground after the team had disembarked, it was apparent one pane of a double-glazed window had been smashed and Liverpool staff were seen cleaning up a pile of broken glass on the ground with Merseyside Police officers in attendance.
“We condemn unequivocally the actions that led to Real Madrid’s team bus being damaged during its arrival to Anfield this evening,” said a Liverpool spokesman.
“It is totally unacceptable and shameful behaviour of a few individuals. 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.”
It is not the first time the opposition coach has been damaged in the build-up to a match at Anfield.
Three years ago Manchester City’s bus was hit by bottles and flares, ahead of another Champions League last-eight clash.
It caused so much damage City had to call for a back-up bus to take the players home after their 3-0 defeat that night.
On that occasion UEFA fined the club 20,000 euros (£17,000) for the damage as well as 6,000 euros (£5,200) for setting off fireworks and throwing objects.