MOSCOW (AFP) - Moscow police were holding almost 400 people under arrest after the Russian capital was rocked by some of its worst ethnically-fuelled rioting in years, sparked by the killing of an ethnic Russian allegedly by a Muslim migrant from the Caucasus.
An initially peaceful protest in the Biryulyovo district of Moscow to protest the killing of Mr Yegor Shcherbakov, 25, rapidly descended into bloody clashes with the police that left the glass doors of a shopping centre smashed and cars upturned.
The crowd chanted "Russia for Russians!" and other nationalist slogans during a protest that swelled to more than 1,000 people in the industrial district of southern Moscow.
Police said Sunday evening that 380 people had been arrested over the rioting and were being questioned as part of a criminal investigation into hooliganism.
Another 14 nationalists were later arrested on a passenger train leaving the area carrying gas cannisters, police said. Six anti-riot police were injured and two are still in hospital.
Moscow police brought in hundreds of reinforcements in a bid to deal with the crisis and enforced their extreme "Vulkan" operation plan which is used in case of a terror attack.
Mr Shcherbakov was murdered overnight Thursday in front of his girlfriend as they walked out of a billiards club.
Media said that security footage showed his killer was a man of "non-Slavic appearance" from the Northern Caucasus, leading nationalists to conclude the murderer was a Muslim labour migrant.
The mass-circulation Komsomolskaya Pravda daily alleged that a fight had begun between the two men after the killer insulted the girlfriend.
Shcherbakov's friends then put pictures of the suspected killer on their social network accounts in a bid to find him.
Tensions have ratcheted up in recent years in big cities like Moscow between ethnic Russians and migrants from Russia's largely Muslim Northern Caucasus as well as the Muslim states of ex-Soviet Central Asia.
The protestors in Biryulyovo accused the police of failing to swiftly investigate the murder and also called on the authorities to toughen up migration legislation.
The topic of immigration was the single biggest issue in September's elections for Moscow mayor won by pro-Kremlin incumbent Sergei Sobyanin, with the top opposition candidate Alexei Navalny also urging a tougher line.
Mr Sobyanin ordered a thorough investigation into Shcherbakov's murder but also called on all those responsible for the Biryulyovo riots to be brought to criminal responsibility.
Local police said that the murderer had hardly left any traces and it was not possible to solve the crime in a matter of days. "We are doing everything to solve the crime," said the police chief for southern Moscow Alexander Polovinka, quoted by Interfax.
After a largely peaceful protest on Saturday, the rioting on Sunday began when a group of protestors attacked a wholesale vegetable market where they thought the suspected killer was hiding.
The protesters threw empty beer bottles at shop windows and hurled clubs and even hammers at a riot police force that rushed to the scene in about a dozen buses.
Wholesale vegetable complexes in Moscow often employ large numbers of migrant workers in shadowy circumstances and Interior Minister Vladimir Kolokoltsev said more had to be done to deal with the situation.
"Otherwise all provocateurs and extremists will use any possibility to get young people onto the barricades," he said at a televised meeting.
The clashes were the worst such ethnically-fuelled unrest since Russian football fans and ultra-nationalists went on the rampage on Manezhnaya Square outside the Kremlin walls in December 2010.
In a similar scenario, they were demonstrating against the killing of an ethnic Russian football fan in a fight with a group from the Northern Caucasus.
"This format of popular unrest has now become standard for the new Russia," wrote columnist Dmitry Steshin in Komsomolskaya Pravda.
"A brutal, motive-less murder of an ethnic Russian by migrants, the impotence of the police and the outburst of 'popular democracy' in its most destructive form."