Eight people have been arrested in Manchester following a city centre brawl before United's 3-2 win over Premier League rivals City.
A group of men were seen fighting and throwing traffic cones in Ancoats, inner city area of Manchester, and were chased by police.
Supt Chris Hill, match commander for the Manchester derby, said a "small number of people" were involved in the disturbance in the city centre before the game but added that officers dealt with it quickly.
He said, as quoted by BBC News: "At such a critical point in the season, there was a lot to consider in policing today's derby, but the match has gone well with only a handful of arrests."
The arrests were for alleged offences including affray, ticket touting and breaching banning and dispersal orders.
United halted City's Premier League title celebrations with a stunning win at the Etihad Stadium, coming from two goals behind to secure a 3-2 victory.
Vincent Kompany's thumping header and Ilkay Gundogan's intricate turn and finish had Pep Guardiola's side in firm control going into half-time.
However, Paul Pogba, on the periphery during much of the first half, scored a quick brace in the second period before Chris Smalling's volley gave Jose Mourinho's side all three points.
City can win the title next weekend but must beat Tottenham at Wembley on Saturday and hope United lose to West Brom, currently bottom of the Premier League, at home on Sunday.