Amsterdam police have made 25 arrests in the red light district of the city in the lead-up to Manchester City's UEFA Champions League match against Ajax.
A spokesman for the city's police force told Press Association Sport that arrests had been made for "public violence" offences after fans from both sets of clubs clashed.
It is not known how many City fans have been arrested, although the majority of those detained are believed to be local supporters.
Police were first forced called into action at 5pm local time when the trouble flared and arrests were made during the ensuing two hours before supporters began to make their way to the Amsterdam ArenA.
"There have been 25 arrests before the Champions League match for public violence, mostly in the red light district," the spokeswoman said.
"Police first took action at 5pm. Most of the fans that have been arrested are from Ajax.
"The city centre was very busy but now as the match approached it is getting calmer and more quiet as the fans head to the stadium.
"We were aware that it would be busy before and after the match and we had deployed extra police to deal with this.
"We hope that it will remain calm after the match."