What began as a peaceful protest over an unsolved killing became Moscow's worst anti-migrant unrest in three years.<br/> <br />Local residents turned out earlier in the day to demand more police action over last week's stabbing of a 25-year-old man they blame on a migrant.<br/> <br />As more swelled the ranks to several thousands the protest erupted into racist chanting, rioting and clashes with police.<br/> <br />Some stormed a vegetable warehouse which employs workers from the Caucasus and Central Asia.<br/> <br />Others attacked a shopping centre and businesses known to employ migrant staff.<br/> <br />Extra police were drafted in to quell the violence although sporadic clashes and arrests went on late into the night.<br/> <br />About 380 people have been detained.<br/> <br />Police said several officers have been injured.<br/> <br />It was the worst unrest over a racially-charged incident in the Russian capital since 2010 when thousands rioted over the killing of an ethnic Russian soccer fan.<br/> <br />The country's top inve
