Jose Mourinho was involved in a furious dressing-room bust-up with Manchester City goalkeeper Ederson as the Manchester derby descended into acrimony.

Sources claimed the Manchester United manager had milk and water thrown at him after the spat with Ederson.

Mourinho was thought to have gone to the door of City’s dressing room to ask their players to show more respect amid apparent disappointment over the way the Premier League leaders were celebrating their 2-1 win, as music blared from the visiting team dressing room.

But a war of words ended up breaking out at that point with Mourinho and Ederson believed to have been yelling at each other in Portuguese as a melee ensued involving players from both sides. There were even reports that Mourinho was hit on the head with a plastic water bottle, with security staff eventually forced to intervene.

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The former Everton and Arsenal midfielder, Mikel Arteta, one of Pep Guardiola’s assistants, was left with blood running down his face after allegedly being cut above the eyebrow in the skirmishes, which evoked memories of the infamous Battle of the Buffet at Old Trafford in October 2004 when Sir Alex Ferguson was hit by pizza after United’s game with Arsenal turned ugly.

Eyewitnesses said that United striker Romelu Lukaku was another prominent figure in the skirmishes which spiralled out of control as police looked on from a distance.

Mourinho later accused City of being “protected by luck” after claiming his team were denied a “clear penalty” against their bitter rivals for the second successive season at Old Trafford.

Ander Herrera was booked for diving by referee Michael Oliver after a challenge by Nicolas Otamendi in the 79^th minute that Mourinho was convinced was a foul by the City defender.

And the Portuguese simmered with injustice after also arguing that United had been denied a penalty in their 2-1 home loss to City in September last year when Claudio Bravo dived into a challenge on Wayne Rooney.

“Manchester City are a very good team and they are protected by the luck, and the gods of football are behind them,” Mourinho said.

“My first reaction is I feel sorry for referee Michael Oliver because he had a very good match but unfortunately he made an important mistake.

“It is like last season, exactly the same. You can speak about anything you want, you can bring any football theory, you can bring the stats, the ball possession, you can bring everything you want but, like last season, it is a huge penalty in a crucial moment of the game.

“Yes they [City] had much more of the ball, yes they had that apparent control of the game but the biggest save is the double save of their goalkeeper [Ederson from Romelu Lukaku and Juan Mata] and the biggest decision of the game is the unlucky decision of Michael [Oliver].”

Mourinho claimed City scored two “disgraceful” goals from United’s perspective – both of which had come from mistakes by Lukaku – but admitted the 11-point gap to City at the top of the table was a “significant distance” and cast doubt over whether his side would be able to bridge it.

“I think when you see Manchester City play, you expect Manchester City to score great goals, not to score two disgraceful goals,” he said. “They are the last goals you expect to concede against a quality team like Manchester City, two very bad goals... with a rebound. Incredible lucky or unlucky, depending on your perspective.

“It is a significant distance [to City now]. I don’t know [if we can make it up]. I know we can win next Wednesday [against Bournemouth]. We can work and fight for it. That is the only thing I say.”

Meanwhile, Pep Guardiola has raised fresh doubts over Vincent Kompany’s long-term future at Manchester City by admitting he can no longer rely on his captain’s fitness.

Kompany was substituted at half time at Old Trafford with yet another injury and Guardiola admitted he was running out of patience. The Belgium defender, who has 18 months left on his contract, has been plagued by injury for the past two years.

“Kompany is injured,” the City manager said. “We wait and see. Vinny is always like this – unfortunately we can’t count on him for a long time.”