In a tweet Jesse Lingard (right) said there is never a reason to be racist (Credit: Reuters/Jason Cairnduff)
Manchester City's Eithad Stadium was the scene of the latest episode of racism in the match against cross-town rivals Manchester United on Saturday.
In a statement Manchester City said it is aware of a video circulating on social media showing a supporter making racial gestures towards United players.
City is working with Greater Manchester Police to identify the individuals and take the necessary action.
"The Club operates a zero-tolerance policy regarding discrimination of any kind, and anyone found guilty of racial abuse will be banned from the club for life."
In a tweet United player Jesse Lingard said "Not even this idiot can ruin tonight's feeling, shameful behavior, it may be the derby but there is never ever a reason to be racist!"
Football commentator and pundit Gary Neville blamed UK Prime Minister Boris Johnson's election rhetoric on immigration for fuelling racist incidents in sport and society.
On Sky Sport after the game he said "You are watching the prime minister's debate where he is talking about migration to this country and people having to have certain levels. It fuels it all the time. It has got worse over the last few years in this country and not just in football."
Racism is an ongoing problem in British football. According to anti-discrimination body Kick It Out, there were 43 per cent more racist incidents in 2018/19 than in the previous season.
"Alarmingly, incidents of racism continue to rise," Kick It Out says in its annual report.
"It remains the most common form of discrimination in both professional and grassroots football, constituting 65 per cent of reports."
But the problem goes wider than the UK too. In October, England players were racially abused by Bulgarian fans in Sofia during a Euro qualifier game, prompting governing body UEFA to imposing sanctions on their national team.