Police have praised fans for their behaviour at the Manchester derby but revealed they are investigating claims Vincent Kompany was racially abused, reports the Manchester Evening News.
Almost 76,000 attended the Old Trafford clash, won 2-1 by City, but officers made just 10 arrests.
The majority of those were for public order offences while two supporters were cautioned for drinking in sight of the pitch.
Meanwhile police have said they are looking at CCTV footage following claims that City skipper Kompany was racially abused after the match in the players' tunnel.
A clip of the post-game interview appears to capture one fan shouting abuse at the Belgian international.
Blues officials have listened to the Sky Sports audio feed of the alleged incident and are satisfied there is no racial element.
However, a Greater Manchester Police spokesman said that they would work with both clubs and look at the footage themselves.