Manchester, December 8: Manchester City are working with police to investigate allegations of racial abuse after Ole Gunnar Solskjaer said two Manchester United players were targeted in the derby.
During the second half of United's 2-1 win at the Etihad Stadium, the visitors' midfielder Fred seemed to be hit by an object thrown from the crowd as he prepared to take a corner.
Lighters and a plastic bottle could be seen by the corner flag while television footage appeared to show a supporter making racist gestures in the direction of Brazil international Fred and his team-mate Jesse Lingard.
Shortly after full-time, City released a statement saying they were investigating and threatened to issue life bans to any individual found to have committed racial abuse.
"Manchester City FC are aware of a video circulating on social media which appears to show a supporter making racial gestures during the second half of the match against Manchester United this evening," their statement read.
"Officials from the club are working with Greater Manchester Police in order to help them identify any individuals concerned and assist with their enquiries.
"The club are also working with GMP regarding an instance of objects being thrown onto the field of play. "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."
Solskjaer confirmed he had seen the incident and he too called for anyone found guilty of such abuse to be banned from grounds for life.
"I've seen it on video, of course," he told Sky Sports.
"Fred and Jesse in the corner taking coins from the City fans, first of all, so they've got to go away. Then there's this not-so-intelligent fella chanting racist abuse towards my two players.
"I hope City and the authorities will deal with it because he shouldn't be watching football again, not live anyway.
"We have to stamp it out. We keep talking about that every single week and it's not acceptable and he should not be allowed back into grounds. That's how simple it is."
Lingard tweeted after the match in response to footage of the alleged incident, saying: "Not even this idiot can ruin tonight's feeling, shameful behaviour, it may be the derby but there is never ever a reason to be racist!"
Anti-racism and discrimination organisation Kick It Out said it had "been inundated with reports of alleged racist abuse from a number of individuals" and called for "swift action" to identify those responsible.
City boss Pep Guardiola added that he supported his club's pledge to take action.
"I think the same as the club," he told Sky Sports.
"I support the club. We are going to work to avoid it happening again."