Russian police detain 1,200 migrants in warehouse raid following ethnic riots Russian police on Monday swept through a vegetable warehouse earlier targeted by rioters, rounding up over 1,000 migrant workers, checking their documents and loading them onto waiting vans to be investigated for criminal activity. The raid came the day after demonstrators angry over the stabbing death of an ethnic Russian man broke into a covered market and descended on the warehouse where they believed the killer was working, throwing bottles and trash, smashing windows and turning over cars. Police detained hundreds of rioters. Men who worked at the warehouse in Biryulyovo, a working-class neighbourhood on the southern outskirts of Moscow, were marched outside by police. Dozens of people gathered at the market nearby to pledge their support to the rioters, venting their anger at the migrants from the predominantly Muslim Caucasus region, whom many Russians accuse of pushing up the crime rate and taking badly needed jobs. Tensions between ethnic Russians and natives of the Caucasus have long simmered, but stand-offs are becoming more common in recent years. Caucasus natives work at many markets and warehouses around the city, but even though they are from the same country they are required to register in order to live in Moscow and face regular discrimination. Andrei Galiakberov, spokesman for the Moscow police, described the roundup of some 1,200 people as part of a "pre-emptive raid" and said that some detainees are being investigated for possible criminal connections. Police also said that they found a car full of cash and unlicensed arms. There was no sign in Biryulyovo of the crushed watermelons and overturned cars from the night before, but the smashed glass doors of the market remained closed for business. Marina Ivanova, who runs a candy stall at the market, turned up for work despite the chaos of the day before. She had been helping customers on Sunday evening when she heard the rioters smashing glass and chanting racist slogans. Ivanova said she didn't take sides, but worried that the conflict could escalate. They'll organize more people and come - both sides. Outside the shopping centre, Elvin Khassan, a 25-year-old who had moved from Azerbaijan to Biryulovo to live with his relatives, faced off with an ethnic Russian man who was waving security camera shots of the suspected killer in his face, shouting, "You are hiding one of your own! Hand him over! Most of those in the crowd said they supported the rioters, who they said could be relied on more than the police to protect the neighbourhood. "They protected us, they are patriots," said Elvira Ablosimova, a retiree. They had a little riot - not a big one - and attracted attention (to the issue). Nationalist parliament member Vladimir Zhirinovsky arrived at the scene, calling the stabbing a "deliberate provocation of the Russian people." But while many were star-struck by his appearance, the crowd remained skeptical. Many average Russians accuse police and politicians of encouraging migrant workers because they are a source of cheap labour and bribe money, which the workers and employers pay to avoid the migration police. "They arrested a (migrant) guy in my building - no papers, nothing," said Alla Vasyanova, a mother of three who lived nearby. He gave them some money, and goodbye. It's just a feeding trough. The politicians aren't on our side. Yegor Shcherbakov, 25, was killed in a dispute over his girlfriend with another man as the couple returned home on Thursday. Sunday's rioters were protesting what they called impunity for the man's supposed killer. Police and investigators on Monday promised to find the man and bring him to justice. Of the hundreds of suspected rioters arrested on Sunday, police kept only two in custody and fined 70 more. Dozens of police officers were injured, and five were hospitalized, police said. The filmed beating of a plainclothes policeman at a market in Moscow spurred a widespread crackdown on the city's migrant workers in August. Police stepped up patrols throughout the city on Monday to prevent a repeat of 2010 riots, when thousands of nationalists and soccer fans protested the killing of an ethnic Russian during a fight between soccer fans and men from the Caucasus.