Police with dogs and riot gear have taken to the streets of Warsaw in the wake of rioting between Russian and Polish fans ahead of their Euro 2012 tie on Tuesday night.
Russian fans were marching through the streets of the capital to celebrate the country's national holiday, Russia Day, when they were confronted by Polish fans.
The two countries have a long, bitter history dating back to the 1700s, as Poland has gone through long periods of occupation by Russia, particularly during the Tsarist 19th and early 20th century, throughout the reigns of Lenin and Stalin and during the Cold War.
The Polish opposition had previously denounced the march, but it has been allowed to proceed by the local authorities.
The march was expected to be provocative, and Russian fans were met by enraged locals, resulting in clashes which had to be broken up by police with smoke bombs.
According to Russia Today, three people have been injured in the confrontations so far.
Riot police have so far been able to separate the two groups, but small pockets of violence are being reported around Warsaw.
The tense clashes are only the latest in a string of unpleasant scandals to hit the tournament.
Multiple accusations of racist taunting from crowds, including against the Netherlands squad, the Czech Republic's Theodor Gebre Selassie and Italy's Mario Balotelli, and violence against stewards at Warsaw stadium, have all tainted the tournament in the opening week.