The arrests came a week after some 7,000 soccer fans and nationalists chanting racist slogans demonstrated near Red Square and attacked passers-by who appeared to be ethnic minorities, injuring more than 30 people.

Russian President Dmitry Medvedev has condemned those attacks, which highlighted simmering ethnic tensions in the country, as "pogroms."

In a sanctioned demonstration on Saturday under the Ostankino television tower in the north of Moscow, hundreds of young ethnic Russian nationalists gathered and shouted slogans such as "Patriotism is not Fascism."

"The rally was sanctioned, but soon the young people got bored, split into groups, and started marching with flaming torches toward the metro. This was illegal of course, and the police made arrests," said Moscow police spokesman, Viktor Biryukov.

Reuters