A man arrested on suspicion of a racially aggravated public order offence during the Manchester derby between City and United at the Etihad Stadium has been released on police bail pending further enquiries.
Greater Manchester Police said investigations would continue.
Anthony Burke, 41, a father from Wythenshawe, was arrested after Saturday's match.
He has now been released from custody after questioning, the force confirmed.
United midfielder Fred appeared to have objects thrown towards him in the second half of the Premier League clash as he went over to take a corner.
Television images then showed what appeared to be a supporter making potentially racist gestures as Fred walked away, holding the back of his head. The video was widely circulated on social media.
Players from both sides appealed for fans to stop throwing objects onto the pitch, before Fred continued the game.
GMP said the force would continue to work with both clubs over the incident.
In a statement released on Monday afternoon, GMP said police were initially called to a report of a supporter making 'alleged racist gestures and sounds'.
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The statement said: "A man that was arrested in connection with reported racist behaviour at the Manchester City v Manchester United match at the Etihad Stadium has been bailed.
"At around 6.55pm on Saturday 7 December 2019 police were called to a report of a supporter making alleged racist gestures and sounds towards players during the Manchester derby.
"A 41-year-old man was arrested on suspicion of a racially aggravated public order and has now been released pending further investigation.
"No further arrests have been made and police are continuing to work with Manchester City and Manchester United football clubs on this incident."
Superintendent Chris Hill of the City of Manchester Division said: "I would like to thank the public for their ongoing support with this incident.
"Racism of any kind has no place in football or our society and I hope this arrest shows that we are taking this matter extremely seriously.
"We will continue to work with Manchester City and Manchester United Football clubs on this incident and will investigate any other lines of enquiries."
City have said that anyone found guilty of racist abuse will be banned from the club for life.
