Before Saturday’s game, Manchester City players and fans paid tribute to their former striker and chairman Francis Lee, who died earlier this month
Manchester City say they will take action after a “small number of individuals” were heard singing offensive chants following the death of Sir Bobby Charlton.
The Manchester United and England legend died on Saturday aged 86.
City have condemned the chants, which were heard in some Etihad Stadium concourses during their game against Brighton on Saturday afternoon.
The club say they are “extremely disappointed” by the reports.
A statement from Manchester City said: “Manchester City FC are extremely disappointed to have learned of reports of offensive chanting from a small number of individuals about Sir Bobby Charlton in some of the concourses of Etihad Stadium during half-time of yesterday’s Premier League fixture against Brighton and Hove Albion.
“The club condemns these chants in the strongest terms and apologises unreservedly to the family and friends of Sir Bobby, and to all those at Manchester United.
“On this day of all days, when the stadium stood to pay tribute to our own legend in Francis Lee, Manchester City supporters should understand and appreciate as keenly as anyone the need for respect in our game.
“Our security team are studying CCTV footage of the concourse areas. We are thankful to those who have already come forward to report this matter.
“We continue to appeal for any information that can help us identify the individuals involved so that we can take the appropriate action to issue banning orders.”
United’s next home Premier League game will be the Manchester derby against City on Sunday 29 October.
In a statement, the Premier League said it was “appalled” to hear about the reports of chanting.
“We welcome Manchester City seeking information on those responsible and will support any subsequent action,” they said.