Police probe as fan slashed in face before English FA Cup match (GRAPHIC CONTENT)
The victim was treated at the scene by paramedics though no arrest was made in connection to the assault amid widespread clashes between the two sets of fans in London on Saturday afternoon.
Images of the victim as well as footage of large-scale brawls were widely distributed on social media in the wake of the incident.
The footage shows dozens of fans throwing punches outside Surrey Keys railway station ahead of the match which took place at Millwall's The Den stadium.
Several police officers, including mounted patrol, intervened and were forced to use batons to quell the disturbance, though police reported no arrests.
"At around 16:42hrs officers became aware of a large group of males fighting in the Hawkstone Road area," a Metropolitan Police spokeswoman said.
"One male aged in his 20s was discovered suffering from a slash wound to the face. He was taken by LAS to a south London hospital. His injuries are not life-threatening.
"A crime scene remains in place. Officers worked to separate the groups with support from the Mounted Branch. At this early stage, there have been no arrests."
Millwall, who are currently in 19th position in the English Championship, have long been connected with the blight of hooliganism. 'The Millwall Bushwhackers' have been active since 1972 and are considered to be among the most prevalent hooligan groups in English football, though it is not yet known who was involved in Saturday's scenes.
"The behaviour of those involved in this incident is nothing short of disgraceful and those involved can be certain we will be working to identify them," Detective Inspector Darren Young, of the South Central Command Unit, said.
Meanwhile, the Football Association has confirmed that it has opened an investigation into alleged racist chanting which is understood to have come from sections of Millwall fans during the game.
The club have announced that they will "ban for life" any supporters found to have engaged in the chants which were discriminatory to people from a Pakistani background.
Don’t think it would be too harsh to throw Millwall out of the FA Cup off the back of those racist chants. If your theory is it’s just “one or two/ a small group of idiots” to blame then you’re wrong. Why punish everyone because of them? Because it needs stamping out, that’s why.— David Preece (@davidpreece12) January 27, 2019
Anti-racism watchdog Kick It Out condemned the fans' actions, adding that racist abuse has "no place in society", while Millwall said that they were "extremely disappointed" by the actions of the supporters in question.
"We reiterate our message: racial hatred - and all forms of discrimination - have no place in society, especially not in 2019. There is no reason why a footballing environment should be the exception to this rule," Kick It Out said of the situation.
"Millwall has a long and proud record of anti-discrimination work and on top of this investigation will continue to work tirelessly, alongside the authorities, to eradicate all forms from the game," a statement from the club read.
Millwall won the game 3-2 with an injury time strike from Murray Wallace securing their progression to the fifth round of the competition.