Middlesbrough fans have been praised for their behaviour during a hostile trip to Rome.
Italian officers with batons were brought in to break up the violence.
Police had appealed for calm ahead of the club's Uefa Cup match against Roma on Wednesday night after three of the English club's fans were stabbed.
Cleveland Police said the attacks on Tuesday night came from an organised gang who targeted bars where the English fans were drinking.
It said Boro fans behaved well despite delays before and after the game.
Supt Steve Swales said despite the fans having to wait for almost two hours after the match finished, they had shown patience.
He said: "I left the stadium after an hour and found the streets back to the city were deserted.
Boro go through to the last eight of the Uefa Cup
"The fans were held back for one hour and 40 minutes. By the time they found their coaches it was almost two hours before they left.
"However, I would like to praise the supporters for their behaviour during this hold-back period.
"While they were no doubt frustrated, they were good natured. They sang and chanted and didn't let their feelings boil over."
Mr Swales said there was an incident after Jimmy Floyd Hasselbaink scored the opening goal when Roma fans ran towards Boro fans.
He said missiles were thrown at the Boro fans and it would be reported to Uefa.
Middlesbrough lost Wednesday's match 2-1 at the Stadio Olympico, the tie finishing 2-2 on aggregate, but went through to the last eight of the Uefa Cup on the away goals rule.