Moscow: Moscow police have stepped up security at the Polish embassy in connection with fighting and rumours of further clashes between Russian and Polish football fans in Warsaw.
"Security measures have been increased due to the possibility of hooligan incidents," a police spokesperson said.
Dozens of people were injured when Polish fans attacked Russians marching through Warsaw to celebrate the June 12 Russia Day national holiday. Police fired tear gas and rubber bullets in an attempt to restore order.
Two Russian fans have so far been jailed for two and three months over their part in the brawl and another four remain behind bars as they await trial. Over 150 Polish fans were detained and just over 20 Russians.
The violence came as Russia and Poland met in a group match at the Euro 2012 championship, co-hosted by Poland and Ukraine. The game ended 1-1.
Russia`s Kommersant newspaper said on Friday, citing a member of a Moscow-based hooligans group, that a group of people was heading to Poland to seek revenge for the Russia Day attack.
Russian fans were also involved in trouble during their first game at the tournament, when a group of fans allegedly hurled racist insults at Czech black defender Theodor Gebre Selassie and threw flares onto the pitch. Fans also unfurled nationalist banners.
UEFA subsequently hit Russia with a suspended six-point penalty for the qualifying stage for the Euro 2016 tournament, to be enforced in the event of a repetition of similar events.
Russia meet Greece in Warsaw on Saturday. Anything but a defeat will see them make the last eight.