Parts of Moscow were in police lockdown on Wednesday as the city remained jittery over possible ethnic clashes following weekend rioting outside the Kremlin.
Hundreds of baton-wielding riot police in dark helmets lined up outside Kievsky train station, which links the capital to southern regions, as authorities towed cars in anticipation of possible clashes.
The area around the station is popular with traders from Russia's southern Caucasus region, and is feared to be a target for the same racist hooligans who rioted outside the Kremlin on Saturday chanting "Russia for Russians!" during clashes that left dozens injured.
Resentment is rising among Slavic Russians over the growing presence in Moscow and elsewhere of people from the Caucasus, the home of numerous ethnic groups, most of them Muslim. People from other parts of the former Soviet Union, including Central Asia and Azerbaijan, also face ethnic discrimination and are frequent victims of hate crimes.
The violence raised fresh doubts about the government's ability to control the rising tide of xenophobia, which threatens Russia's existence as multiethnic state.
The weekend rally began as a protest against the killing of a member of the Spartak Moscow football team's fan club, who was shot with rubber bullets in a fight with Caucasus natives at a bus stop earlier this month.
Spartak fans were further incensed with how Yegor Sviridov's killing was handled by police. They claimed that while police arrested one suspect following the fight, they released others because they had powerful backers in the Caucasus. Moscow police chief Vladimir Kolokoltsev acknowledged Monday that investigators had made a mistake and said three more suspects have now been arrested.