Police have confirmed that Sunderland football fans were not involved in violent riots following the Tyne-Wear derby match on Sunday.
The trouble erupted several hours after the match in Newcastle
Fifty people were arrested when trouble flared in Newcastle following Sunderland's 3-2 defeat.
But the drink-fuelled trouble, which at its height involved 300 people, did not involve Sunderland fans.
Northumbria Police said that "well known" football hooligans from Newcastle were responsible.
During the 12-hour period after the match a total of 50 people were arrested in the city centre in connection with violence, drunkenness and disorder offences.
Police said many of the arrests were made in the city's busy Bigg Market area.
Assistant Chf Con Kevin Mathieson said: "Yesterday's football match between Newcastle United and Sunderland AFC passed off with very few problems and generally both sets of fans behaved themselves.
"There were, however, outbreaks of disorder in the evening, many hours after the match had ended.
"There is nothing to suggest the disturbances involved Sunderland supporters.
"However, there is an indication that some of those involved were well known football hooligans from Newcastle."
Mr Mathieson said that officers were reviewing CCTV footage and vowed to track down those responsible for trouble.
He added: "We had extensive resources available and deployed them to the Bigg Market where some robust policing helped dissipate the crowds."