Roma fans have been seen in Kensington fighting with police and throwing bottles at officers ahead of their Champions League clash with Chelsea.
A witness said officers were forced to charge a group of fans on Wednesday (October 18) afternoon.
Police said later that one man had been arrested.
Gary King was leaving his office on Kensington High Street at around 5.40pm when he saw events unfold.
He said: “I saw a group of maybe 30-40 people and they were being escorted down the road by police.
“I initially thought it was some sort of protest but then saw some of them were wearing Roma scarves.
“The police were trying to keep them on High Street Kensington but a group of about 15 tried to break off and run down Wrights Lane.
“A couple of police ran ahead to stop them and a bit of a scuffle broke out. Then more officers came along.
“A couple of them threw bottles.
“Then about eight to 10 police officers charged them and the fans ran back to the main group on the high street."
Scotland Yard confirmed it had been called to reports of a disorderly group in High Street Kensington at around 5.45pm.
A spokesman said officers attended and dispersed the group, and that one man was arrested.
Mr King, from Fulham, said a couple of the officers present were equipped with helmets and shields, but the majority were regular officers.
All had their batons out, he added.
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