Three supporters were hospitalised after a flare-up on the way home from a friendly match at the weekend.
The Independent Police Complaints Commission is investigating the incident, which happened at Newcastle Central Station as 40 supporters returned from Sunderland's game at Hearts, Edinburgh.
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Watch shocking video of the incidentNorthumbria Police say four of their dogs were injured by violent fans intent on causing trouble, and vowed to track down those responsible and to get them banned from football.
However, many Black Cats supporters have accused officers of sparking the incident by mismanaging the situation and using excessive force.
They today spoke of submitting formal complaints and legal action.
Police said the injuries sufered by the fans who needed hospital treatment were "not thought to be serious."
But self-employed joiner Allan Brown fears he may be off work for months with injuries he says were caused by an officer's baton.
The 31-year-old, from Seaham, said he was kept in hospital overnight and has been left with an eight-inch and a seven-inch wound to his head.
Mr Brown claimed the problem was caused by police with unmuzzled dogs behind the fans forcing them forward into another line of officers holding them back.
"Then they let the dogs off," he said. "As we were trying to get away there were truncheons coming down on top of us."
Mr Brown said he was today seeing a solicitor about suing for compensation.
One fan needed staples to a head wound, which he said happened when he was hit with a baton after he fell to the ground.
He can be seen on video lying on the concourse in a pool of blood.
Fans had been told they were on a Football Special direct to Sunderland, so did not exptect to arrive at Newcastle Central.
A 28-year-old Sunderland man, who now lives on Tyneside and works as an IT technician, said: "Before we even got off the train they had the dogs and batons out and the dogs were unmuzzled.
"There had been no trouble on the train at all. We'd just been having a good laugh.
"I thought the police were disgraceful for what they did. People were pushing forward and they just set the dogs on them."
Teacher David Storey, who spent 24 years in the armed forces, said a teenage Sunderland fan was pushed on to the police cordon at the front as officers at the back screamed at the group to go forward.
"One of the dogs bit him. You could see the bite marks across his stomach."
Mr Storey said fans tried to grab the youth back and chaos ensued.
"They let the dogs off and the batons started coming down, bludgeoning people in the head.
"Two lads get very, very serious head injuries and several lads got mauled by the dog.
"I really thought one of the guys was dying in front of us as his head was spurting blood all over with a visible pumping spurt.
"By this time there was a scene of utter carnage. There were literally pints of blood all over the platform floor and three lads needed critical medical help.
"I did not at any time see fans do anything that warranted the savage attack by the police."
He added: "There were a lot of very angry, shocked and traumatised Sunderland fans as we boarded the train.
"I have always defended the police whenever I have heard people disrespecting them or criticising their use of force. No longer though."
Newcastle Police made one arrest for drunk and disorderly behaviour.
But they said they would use CCTV to help prosecute those they accused of causing the trouble, which saw four police dogs – Clio, Floyd, Earl and Diesel – "kicked and punched to the ground and then stamped on."
The incident happened at 8pm on Saturday.
Police accuse supportersA PLANNED police operation was in place to ensure Sunderland fans were kept away from Newcastle supporters and "ushered safely" to the Metro Station.
But the force said a section of Black Cats fans "became violent and disorderly and lashed out at police officers and dogs."
Chief Superintendent Graham Smith, Newcastle Area Commander, said: "The fans arrived at the station intent on violence and our dogs have never faced that level of assault before.
"Thankfully, although shocked, battered and bruised, none of them have been seriously injured and all are now at home recovering."
Police have asked anyone with information to contact them on 03456 043 043.
Fans' Federation offer supportTHE Football Supporters' Federation (FSF) has offered assistance to Black Cats fans involved in the incident.
Chairman Malcolm Clarke said: "The FSF is very concerned indeed to learn of these events, and note that there are startling discrepancies between the accounts from many supporters and the police statement of what occurred.
"It is essential that there is a full, independent investigation into what happened."
Fans can either call 0870 2777777 or email Amanda.Jacks@fsf.org.uk.