A massive race-tinged riot outside the Kremlin walls has exposed the problems Russia faces as it prepares to present a modern new face to the world at the 2018 World Cup.

President Dmitry Medvedev said Saturday’s clash between the police and some 5,000 ultranationalists and football hooligans threatened the stability of the entire state.

“These actions threaten the stability of the state,” Mr Medvedev said, vowing to bring all those responsible to justice.

Saturday’s violence sent more than a dozen people to hospital and degenerated into a tension-fraught weekend that saw sporadic reports of violence throughout the Russian capital.

Reports said one Central Asian man was mobbed and killed by a gang of more than 15 youths on Sunday evening while Nazi chants were heard at various Moscow metro stations on Saturday night.

As tensions continued yesterday, hundreds of anti-riot police closed off Red Square and another square in front of the Kremlim amid fears of a repeat of a violent protest by far-right football fans.

Media and rights advocates both warned that the ugly scenes of hooded youth chanting “Russia for Russians” exposed a racist malaise at the heart of Russian society just a week after it was awarded the right to host the 2018 World Cup.

The initial tension was sparked by the death of Yegor Sviridov – a Spartak Moscow fan who was shot in the head on December 4 during a fight with men from the Russia’s predominantly Muslim North Caucasus.

The link between the extreme right and football fans – some of whom model themselves on British hooligans and call themselves “firms” – will be watched closely by the authorities as Russia prepares to host the 2018 World Cup.

Media reports said Sviridov was an active participant in one of Moscow’s most aggressive fan groups known as The Union.