I'm not really sure if this thread belongs on /sp/ or /int/.. but do other countries have intense sports rivalries between different regions of the country?? In the U.S. it's common for their to be i'd say around 10 fights that break out per year due to these rivalries.
I remember a few years back a football game almost got cancelled because two teams almost got into a full on team vs. team brawl when they first left the locker room.