New video footage from Barcelona shows scenes of riot police officers in a stand-off with Liverpool fans.
In the video, taken yesterday afternoon by fan Johnny Martin at Plaça Reial, some supporters can be seen throwing drinks and missiles at the white-helmeted Spanish police.
It is now believed these scenes followed the earlier incident of a man being dumped in a fountain in the square where fans had congregated.
Wes Lee, who witnessed the scenes yesterday, said: "My wife and I were in the square yesterday evening when the police came in.
"I don't know what started it, apparently there were reports of some Liverpool fans pushing locals into the fountain which if true is stupid and the actions of a few may ruin it for the rest of us.
"In my opinion it could easily have been avoided if there was a slight police presence in the square. After all it is where they wanted us to congregate."
He added: "The police did seem to come in very heavy-handed. With batons, they even forced my wife who has cancer into a corner in the square, she was clearly terrified but they kept shouting at her.
"There just seemed to be a lack of common sense with it all. I was in Rome last year and it was so much better organised. I just hope that tonight goes well and without any problems."
Merseyside Police today confirmed six men had been arrested by Spanish officers, amid reports Liverpool fans had injured hotel staff in the square.
