Resentment has been rising among Slavic Russians over the growing presence in Moscow and elsewhere of people from the southern Caucasus region, the home of numerous ethnic groups, most of them Muslim. People from other parts of the former Soviet Union, including Central Asia, Armenia and Azerbaijan, also face ethnic discrimination and are frequent victims of hate crimes.
New scuffles erupted Wednesday outside the Kievsky train station, which is popular with street merchants from the Caucasus. Hundreds of riot police were deployed and they detained young men and teenagers shouting racist slogans.
Some men who appeared to be from the Caucasus also were detained, while others were let go after a quick check. Most of those detained Wednesday were rounded up at the Kievsky station, where officers also confiscated dozens of knives and other weapons, police spokesman Viktor Biryukov said.
The area around Kievsky station was feared to be a target of those who rioted outside the Kremlin, mainly soccer fans, who chanted "Russia for Russians!" during Saturday's clashes that left dozens injured. Many soccer fans are linked with neo-Nazis and other radical racist groups that mushroomed in Russia after the 1991 Soviet collapse.
Russian media have been abuzz with rumors that some people from the Caucasus could try to take revenge for Saturday's riots, even as community leaders described the allegations as a provocation and called for calm.
A shopping mall just outside the station shut down hours ahead of schedule, and most stands at a nearby flower market, operated mostly by people from the Caucasus, were shut. Authorities towed cars early in the morning in anticipation of possible clashes.
The weekend rally began as a protest against the killing of a member of the Spartak Moscow soccer team's fan club, who was shot with rubber bullets during clashes with Caucasus natives at a bus stop earlier this month. Spartak fans claimed corrupt policemen detained one suspected killer following the fight, but they released others because they had powerful backers in the Caucasus.