Local reporters said the protesters gathered in the Biryulyovo District to urge police to detain the suspect in a recent murder case and also to call for tighter migration law in light of the fact that the suspect was allegedly a migrant.

Witness accounts put the overall turnout at several thousand people, Reuters reported. The protests focused on the local police headquarters and on a shopping center reportedly targeted for the high numbers of migrant workers employed there.

Some protesters forced their way into the shopping center, breaking glass and setting off smoke bombs, journalists at the scene reported. They were also reported to be targeting a nearby vegetable market.

Videos and photos show protesters tipping over cars, storming a kiosk, setting up barricades from trash cans and assaulting immigrants. Blogger Ilya Varlamov wrote that traffic was blocked throughout the entire Biryulyovo district.

Protesters also threw bottles, rocks and sticks at police and attacked some of the police officers, he wrote, posting a photo of an officer with blood on his face.

According to Interfax, more than 200 people had been detained by 8 p.m. as the rioting continued.

Moscow police said Sunday evening that they had detained seven people on hooliganism charges over the violence and opened a criminal case over the riots.

The murder that triggered the protests happened on Thursday night early Friday morning. A 25-year-old man was fatally stabbed as he was returning home with his girlfriend, a statement on the Investigative Committee website says.

Local law enforcement agencies have circulated CCTV footage of a man they believe to be the main suspect. Russian media have identified the alleged attacker as a migrant.

Meanwhile, soccer fans were making their way to the area from the Paveletsky train station, Dozhd reported.

Moscow police chief Anatoly Yakunin announced earlier Sunday a reward of up to 1 million rubles (about $30,975) for identifying the suspect in the high profile murder case.

He also urged "members of the diaspora" to assist police in their investigation into the attack.

Meanwhile, the Investigative Committee said that it had taken control of the investigation, apparently in an attempt to reassure the public.

Moscow police said Saturday that as part of their inquiries into the murder, they had identified and detained 87 "foreign citizens, illegally residing in the Russian Federation."

In recent years, Russia has seen a series of high-profile crimes with a racial or ethnic component over which locals come together to express their outrage in unsanctioned protests.

These are often directed at what many see as the authorities' inability or unwillingness to hold perpetrators liable, as well as at the ethnic community at large.

These unsanctioned protests are dubbed "narodny skhody" or "popular gatherings," a reference to the term "skhod" or "skhod grazhdan" (citizens' gatherings) that can be traced back through Russian, Soviet and pre-Revolutionary law as part of local government.

**Material from the Moscow Times was included in this report.