Nearly 70 members of Biris Norte (Sevilla FC, left-wing) travelled to Madrid some weeks ago because of the match their team played with Atlético de Madrid. Most BN members were banned years ago after some incidents in Madrid, so they cant go to Spanish State capital football grounds. Two or three years after, that banning order have expired, and so they travelled there to face Frente Atlético (Atlético de Madrid, right-wing). Those two groups are, nowadays, the two top groups of the Spanish League with Bilbao's Herri Norte Taldea.
There are some little videos of the fight, happened in the center of Madrid. Only 6 sanctioned (5.000 euros fine of each one and a banning order of two years).
PD: The ones that run are Frente Atlético, but they are escaping after the police intervention in a, aparently, fair and equaled fight.