Police warning for Manchester football fans
Football fans in Manchester have been warned to be on their best behaviour during the city's first derby of the season.
Greater Manchester Police said it would "clamp down" on anyone causing trouble.
Ch Supt Mark Roberts said police would be on high alert around Old Trafford, where the game between United and City takes place, and in the wider city.
"It must not be used as an excuse by some fans to carry out football-related violence and disorder," he said.
The police are said to have been heartened by recent gestures of goodwill between the two teams.
This included Man City officials laying a wreath at the memorial to the 1958 Munich Air Disaster, in which several United players were among the victims, on a recent trip to Germany.
However, Mr Roberts said the force was aware there was still plenty of animosity between the fans.
"We want fans to enjoy themselves, but at the same time, we want to make it clear to the minority of fans who may be thinking of causing any trouble that we will clamp down hard on them," he said.
"Both Manchester United and Manchester City are supportive of the fact that anyone who is arrested in connection with causing trouble at the derby or in a related incident elsewhere this weekend, runs the risk of being banned from entering their respective clubs again in the future.
"The rivalry between the clubs really adds something extra to this fixture and should be embraced, but we must also ensure this is not used as an excuse by some fans to carry out football-related violence and disorder."