Sorry mate, someone has been telling you porkie pies.
Such an incident never happened. NO group is more controlled by huge police numbers as a football crowd (and Leeds are notorious for hooliganism btw, which is another reason why this story is bunkum), the British police will be there at the train/bus station or car parks when fans arrive and they will corral them and march them to the stadium, then the same back after the game.
The idea that UK police would allow a football crowd to wander freely is nonsense, and the idea that they would ‘deliver’ them into a group of Muslims is even more nonsense.
Also, if there is a football game on, NO political march would be allowed in the same city or town, due both to the police numbers needed and the potential for violence.
If you have read this story online, I can assure you its not true. For the reasons given above.
I think that was a mangled reporting of a UKIP rally.
The Muzzies counter protested (and, according to what I have heard, were violent throwing bottles and whatnot). But the cops busted up the UKIP (which had the required permits, etc), not the Muzzies.