Chelsea and Manchester City fans got into a violent clash with Porto Police on Thursday night before the Champions League final.
English Fans have been arriving in Porto over the last few days for the Champions League final on Saturday.
Chelsea and Manchester City fans clashed with Police after local bars in Porto were closed at 10.30pm.
There were no serious injuries sustained from the incident.
Manchester City face Chelsea in the Champions League final in the Estadio do Dragao on Saturday.
Only 16,500 fans are allowed to watch the match in the stadium, 33 per cent of the 50,000 stadium capacity.