Football fans are gathering in their national colors in the Polish cities of Warsaw and Wroclaw ahead of two decisive games at the European Championship that will determine who advances to the quarterfinals.
Thousands of Russia supporters are in Warsaw to watch their team play Greece, with police on high alert for a potential repeat of clashes between Russian and Polish hooligans that marred a group match between the fierce rivals on Tuesday.
The two countries were enemies for centuries and authorities fear more street brawls in the capital. Police used rubber bullets and tear gas to combat Tuesday's violence and more than 200 arrests were made.
In Wroclaw, co-host Poland plays the Czech Republic to decide the other quarterfinalist from Group A.
