It was previously reported Russian fans were planning a march through the city before the game to mark a national holiday, which caused an increased police presence on the streets. Apparently, that wasn't enough to stop the clash.
Police have since attempted to move the two sides apart to keep the fights from escalating into a major brawl. The BBC's Dan Roan reports the Russian march has been stopped with hopes that will ease the tension with still a couple hours until kick off.
Authorities are always forced into a difficult situation when two countries with as much history as Poland and Russia play a major sporting event. Those concerns are raised even more when the match takes place on the home soil of one side, like is the case today for Poland.
Judging by the initial reports, it appears the police have done a nice job of making sure things didn't get totally out of control at any point. It's nearly impossible to stop all the violence, so avoiding a complete tragedy should be the main focus.
Spoke too soon: ultras now clashing on far side; copters and cops scrambling. Footage soon on FOX Soccer— Jamie Trecker (@JamieTreckerFOX) June 12, 2012
It's unclear how violent those clashes have become, but it's clear the police have their hands full right now.