Manchester City have said they will ban any fans found to have engaged in offensive chanting about the death of Sir Bobby Charlton during their Premier League game with Brighton.
The Manchester United legend died on Saturday. He was 86. The news was announced at halftime of City's 2-1 win over Brighton and City said "a small number" of fans were heard chanting in the concourses at the Etihad Stadium.
A City statement read: "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, and 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 and City are set to meet in the Manchester derby on Sunday. Ahead of the game, a number of City fans paid their respects to Charlton by leaving scarfs at Old Trafford over the weekend.
Following City's statement about their investigation into the chanting at the Etihad, the Premier League said they will support any action taken by the club.
A statement issued by the Premier League read: "The Premier League is appalled to hear reports of chanting related to Sir Bobby Charlton at the game at the Etihad Stadium.
"We welcome Manchester City seeking information on those responsible and will support any subsequent action."