Regarding the incident, from what I've been able to read from various sources(English, German and Serbian) , the incident happened in a bar where a big group of Serbian supporters were meeting up. The bar even had a Serbian flag displayed in front of it, as evidenced by most videos. Some English fans were there as well and had drinks with Serbian fans in peace, when a group of Albanian fans entered the bar and started the fight. English fans weren't involved directly, only some fans that were caught in the middle of everything.
It's a shame things like this always seem to happen, regardless of nationality. Similar things happened in the past with English, Serbian and fans of many other nations. I don't get why some people enjoy picking up fights for no reason.