Up to 50 police officers were injured after trouble erupted following Millwall's Division One playoff defeat to Birmingham City, Scotland Yard said today.
Police said several hundred disgruntled Millwall fans left the stadium with the aim of assaulting the Birmingham supporters who had travelled to the New Den in Bermondsey, south London.
Police said they threw missiles, including bricks, paving stones, flares and fireworks. Six police needed hospital treatment. A spokeswoman said at seven people were arrested - four during the game and three for disorder after the game.
Most of the Birmingham supporters had travelled by coach and were delayed for more than an hour before they could leave the stadium due to the violence.
The 21 coaches containing Birmingham supporters were then escorted from the area and about 50 police officers dressed in riot gear escorted a group of about 200 Birmingham City supporters into London Bridge tube station.
During the violence outside the ground, one officer was injured when he was kicked by a police horse. Another injured police officer had to be rushed through London Bridge station by two paramedics.
Police also said two cars were set on fire outside the ground and that the fire brigade was unable to reach the fires because of the disorder. Officers later cleared the scene and the fires were put out.
PA