Greater Manchester Police (GMP) have warned fans they will crack down on any troublemakers at Sunday's FA Cup derby clash at the Etihad Stadium.
There have been problems at City home games against United in recent seasons, with 29 arrested after the Carling Cup semi-final first-leg tie two years ago. Further disturbances have scarred the latest contests and there are fears the size of United's 5,700 visiting contingent this weekend creates the potential for even more problems.
GMP Assistant Chief Constable Terry Sweeney said: "The close rivalry between the clubs really adds something extra to this fixture and should be embraced. But we must also ensure that this is not used as an excuse by some individuals to carry out football-related violence and disorder."
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