Romelu Lukaku
Soccer Football - Premier League - Southampton vs Manchester United - St Mary's Stadium, Southampton, Britain - September 23, 2017 Manchester United's Romelu Lukaku applauds the fans after the match Reuters/Tony O'Brien

Manchester United are planning to come down hard at disruptive supporters who continue to sing a controversial chant about Romelu Lukaku. During Saturday's 1-0 victory over Southampton, the Belgian striker was once again subject to a chant that United has deemed as "offensive behaviour."

The club have asked CCTV footage of the away game at at St. Mary's Stadium to identify fans who engaged in the chants. After the game, the song was condemned by Kick it Out, an anti-decimation group in the U.K.

The club said in a statement: "Manchester United has a zero tolerance stance on offensive chanting and behaviour. The club and player have been clear in asking for an end to the chant. The club has worked with relevant bodies and supporters groups in trying to eradicate any offensive behaviour and will take further action against individuals if this continues.

"The club is in discussion with the police and has asked for CCTV footage from Southampton and will try to identify those who disrespected the player's wishes not to sing the song."

Manchester United to review CCTV footage of game

The song, which makes a reference to Lukaku's penis size, grew louder after the Belgian netted a goal at the 20-minute mark Saturday evening. Last week, United tweeted a quote from Lukaku, with hopes that the supporters would "move on" from the song.

However, after the song returned at Southampton, having previously been heard during games against Basel and Everton, United decided to act. Jose Mourinho, manager of Manchester United, downplayed the song and insisted he had not heard it.

"I don't understand what the fans sing. The only music I understand clearly is one from my opponents when they tell Mourinho to go to a place. That's the only one I understand. But the only thing I will say is the fans were amazing, the support amazing from the first to the last minute," the Portguese manager said.