The Football Association has said it will take no action over the tunnel clashes which followed Manchester City’s win at Manchester United this month.

Police officers and stewards had to separate up to 20 players and members of staff from the clubs after a bust-up in which bottles and punches were thrown and Mikel Arteta, one of City’s coaches, was left with blood streaming down his face.

The FA said in a statement: “Following a review of the evidence provided by the clubs and independent eyewitnesses the FA will be taking no formal action.”

Each club believed the other to be culpable and it is thought the FA received contrasting accounts of what happened.

The FA initially asked for background reports, then asked for further information from several witnesses. A spokesman said: “We spoke to quite a lot of people in the end, before satisfying ourselves there was no need to take the matter further.”

José Mourinho will also not face FA action over comments he made before the derby but has been warned that “any further public comments about match officials may result in disciplinary action”.

The FA did not specify which remarks it was investigating but it is understood to have been concerned by the United manager calling on the referee to be alert to what he described as City’s “tactical fouls”.