Cape Town - Liverpool were forced to apologise after Manchester City's team bus was pelted by bottles and cans ahead of their highly-charged Champions League quarter-final on Wednesday.
Liverpool supporters surrounded the roads around Anfield and let off flares before throwing bottles at the City bus around an hour before kick-off.
The bus was reportedly rendered unusable by the damage and City sent for another for the post-match journey home.
Liverpool manager Jurgen Klopp apologised, saying: "Absolutely, I really don't understand it. We tried everything to prevent a situation like that. For Liverpool FC I have to say sorry."
A frustrated Pep Guardiola admitted his surprise at the scenes before the game especially after Borussia Dortmund's team bus was attacked last season with explosives.
"We didn't expect that after what happened last season in Dortmund I didn't expect that," he said.
"I know that is not Liverpool, the history of the club is much bigger than this four or five or 10 guys. Hopefully it doesn't happen again."
However City Captain Vincent Kompany refused to blame the hostile Anfield reception for their 3-0 loss that leaves his side with a slim chance of progressing to the semi-finals of the Champions League.
"It means nothing, we're professionals and the game came down to key moments. We got a nice reception here and when they come down to Manchester they'll get the same down there.
"We absolutely still 100% believe we can do enough to progress through to the next stage of the competition."