Two football clubs have threatened unruly supporters with life bans after trouble at a friendly game which resulted in five arrests.
Notts County said the trouble was an "absolute disgrace"
Hundreds ran onto the pitch at the end of Monday's match between Notts County and Nottingham Forest at Meadow Lane.
There were fights inside the ground and violence erupted on the streets later.
Police said they deployed "every available officer" in the city while both clubs said they would look at CCTV footage to identify the offenders.
Notts County chairman Jeff Moore said: "It's an absolute disgrace. I just don't know what we do to prevent such idiocy that exists in our society today."
Forest chief executive Mark Arthur added: "Any people... causing serious havoc will receive banning orders from both the City Ground and matches we play away from home.
"We do not want any behaviour like that to tarnish the good name of Nottingham Forest."
Forest won the game 2-1.