Manchester United and Manchester City will face no further action over the tunnel fracas earlier this month, the FA has said.
A statement from English football's governing body said: “Following a review of the evidence provided by the clubs and independent eyewitnesses The FA will be taking no formal action."
Players and staff became embroiled in a brawl after City's 2-1 win at Old Trafford, with the two clubs blaming each other for the melee.
United claimed their rivals' excessive celebrations sparked the scuffle, however City suggested that United manager Jose Mourinho provoked a reaction among their players by acting aggressively.
City coach Mikel Arteta emerged with a cut to his face, while reports suggested United striker Romelu Lukaku had thrown a bottle - a claim which prompted Mourinho to challenge the accusers to show evidence.
City's victory, secured with a second-half goal from Nicolas Otamendi, was seen as crucial in the title race, giving them a huge 11-point lead over United.
The feud between the two clubs has shown no sign of softening in the fortnight since the Old Trafford match, with Mourinho criticising City for a lack of respect and City players filmed singing a derogatory song about the United manager following their 4-1 victory over Tottenham at the Etihad Stadium.