Police made 21 arrests in Sunderland as the Black Cats' 20th anniversary match against Celtic was marred by violence.
Northumbria Police confirmed today that they made 21 arrests, but could not say whether they were Sunderland or Celtic fans.
The majority of the arrests were for drunk and disorderly, breach of the peace and the use of illegal pyrotechnics.
The Glasgow club brought an estimated 8,000 supporters to the match, which also marked the 50th anniversary of their 1967 European Cup win.
Before kick-off, social media became awash with images of rival fans involved in running street battles in the Monkwearmouth area.
One local news agency reported Celtic fans being attacked near the Stadium of Light by a coachload of hooligans singing God Save The Queen.
In Hendon, a Celtic fan was seriously injured in an incident outside a shop where former English Defence League leader Tommy Robinson was making a personal appearance, dressed in a Rangers top.
In video footage of the incident, the fan wearing a green and white hooped shirt appeared to be felled by someone brandishing a weapon.
He was shown being treated by police while they waited for an ambulance to arrive, with his head resting on a Union Jack cushion.
Robinson had previously posted videos of himself referring to Celtic's hardcore followers the Green Brigade as 'muppets'.
The man injured in the incident outside the shop was taken to Sunderland Royal Hospital, where his injuries were found to be not life-threatening.
A police spokesman said: "One incident occurred at Fletcher’s Off Licence in Hendon, Sunderland, whereby an 18-year-old man was taken to hospital with a head injury.
"The man has since been discharged from hospital. Police inquiries are still on-going to determine the details of the incident."
Some fans blamed a far-right element for causing trouble in the city before the game.
One onlooker said: “All the bars around the Stadium of Light were full of Celtic fans singing and having a nice time.
“At about two o’clock a white coach pulled up and off got a lot of soccer thugs. They did not have any identifiable colours of football teams.
“They were singing anti-IRA chants and ‘God Save The Queen’."